Heart health and physical activity

New research, appearing in the European Heart Journal, suggests that lack of physical activity can drastically increase the risk of a heart attack in the long-term, even if there are no symptoms at present.
running and heart fitness
Exercise that raises the heart rate, such as running, may cut heart attack risk by half, suggests a new study.

Cardiorespiratory fitness describes the body’s ability to deliver oxygen to the muscles when we are engaged in physical activity. Specifically, the term refers to “the efficiency of the heart, lungs and vascular system.”

A significant body of research has linked cardiorespiratory fitness with a variety of positive health outcomes, ranging from preventing cardiovascular disease and all-cause mortality to staving off diabetes and improving insulin resistance.

However, most of these previous studies have relied on the participants’ self-reported levels of fitness.

New research uses more precise methods of measuring cardiorespiratory fitness and highlights another one of its benefits.

Higher fitness levels can halve the risk of heart attack, the new study finds. Conversely, suggest the researchers, poor fitness levels can raise future risk even in the absence of warning symptoms in the present.

Bjarne Nes, from the Norwegian University of Science and Technology’s Cardiac Exercise Research Group in Trondheim, is the corresponding and last author of the study.

Studying fitness levels and heart attack risk

Nes and his colleagues analyzed the cardiorespiratory fitness of more than 4,500 people who took part in an extensive health survey called HUNT3.

None of the participants had a history of cardiovascular disease, lung disease, cancer, or high blood pressure at the start of the study.

Just over 50 percent of the participants were women, and more than 80 percent of all of them were at “low risk” of developing cardiovascular disease over a 10-year period.

The scientists used a “gold-standard method” — or maximum oxygen uptake — to directly measure the participants’ fitness levels.

Maximum oxygen uptake refers to the maximum amount of oxygen the body can absorb during exercise. According to Nes, it is “the most precise measure of fitness.”

High fitness halves the risk of heart attack

By the end of the study, 147 of the participants had heart attacks or had developed angina pectoris — two conditions caused by blocked or narrowed coronary arteries.

The analysis by the researchers revealed a correlation between declining cardiovascular risk and increased fitness levels.

“Even among people who seem to be healthy, the top 25 percent of the most fit individuals actually have only half as high a risk as the least fit 25 percent,” reports Nes.

Furthermore, even a small improvement in cardiorespiratory fitness saw significant benefits for heart health. Namely, each fitness increase of 3.5 points correlated with a 15 percent lower risk of heart attack or angina.

“We found a strong link between higher fitness levels and a lower risk of heart attack and angina pectoris over the 9 years following the measurements that were taken,” says Nes.

“We know that patients with low oxygen uptake are at increased risk of premature death and cardiovascular disease,” he continues.

Our study shows that poorer fitness is an independent risk factor for coronary artery disease, even among healthy women and men who are relatively fit.”

Bjarne Nes

‘Use training as preventive medicine’

Dr. Jon Magne Letnes, the study’s first author, also further comments on the findings. “Our results should encourage people to use training as preventive medicine,” Dr. Letnes says.

“A few months of regular exercise that gets you out of breath can be an effective strategy for reducing the risk of cardiovascular disease.”

Dr. Letnes explains that cardiorespiratory fitness offers insights into so much more than just endurance to exercise.

“Fitness isn’t just a measure of how much you’ve trained in your life, but it also tells you what kind of genes you have,” he says.

“Other factors like obesity may also affect fitness. So we measure a lot of the body’s functions, and from other studies, we know that both genes and physical activity play a role in how your heart and blood vessels function,” Dr. Letnes explains.

The study’s first author thinks doctors should consider fitness measurements when evaluating heart disease risk.

“Although it may be inconvenient and difficult to measure oxygen uptake at the doctor’s office, some simple and relatively accurate calculators exist that can provide a good estimate of fitness and disease risk,” he advises.

Xylitol low calorie substitute

Xylitol is a lower-calorie sugar substitute with a low glycemic index. Some research suggests that it may also improve dental health, prevent ear infections, and possess antioxidant properties.

Xylitol is a sugar alcohol, which is a type of carbohydrate and does not actually contain alcohol. It occurs naturally in small amounts in fibrous fruits and vegetables, trees, corncobs, and even the human body.

Manufacturers use it as a sugar substitute because its sweetness is comparable with that of table sugar but with fewer calories.

It is also a common ingredient in many products, from sugar-free chewing gum to toothpaste. People also use it as a table-top sweetener and in baking.

This article looks at the uses and potential health benefits of xylitol. It also covers its side effects, drug interactions, dosage, and alternatives.

Uses

Xylitol sweetener on wooden spoons
A low-calorie alternative to sugar.

Xylitol has a similar level of sweetness to sugar but with a fraction of the calories. It is a popular ingredient in a variety of products, including sugar-free gum and toothpaste.

Manufacturers add it to a range of foods, including:

  • sugar-free candies, such as gum, mints, and gummies
  • jams and jellies
  • honey
  • nut butter, including peanut butter
  • yogurt

It is also an ingredient in some dental care products, including:

  • toothpaste
  • mouthwash
  • other fluoride products

Potential benefits

Xylitol has several potential health benefits, including:

Low glycemic index

It has a low glycemic index (GI). This means that consuming it does not cause spikes in blood glucose or insulin levels in the body. For this reason, xylitol is a good sugar substitute for people with diabetes.

Due to its low GI, it is also a weight loss-friendly sugar substitute.

Also, a 2015 study revealed that it had significant blood glucose-lowering effects in rats that ate high-fat diets.

Dental health

Xylitol is an ingredient in many dental hygiene products, including toothpaste and mouthwash. This is due to the fact that it is non-fermentable, which means that the bacteria in the mouth cannot convert it into the harmful acid that causes tooth decay.

The oral bacterium Streptococcus mutans is largely responsible for plaque, which is the sticky, white substance that can accumulate on the outside of a person’s teeth.

Plaque binds lactic acid against the surface of the tooth. This acid breaks down the enamel and leads to tooth decay.

While it is normal for people to have some plaque on their teeth, excess amounts can lead to tooth decay, cavities, and gum disease.

A 2017 systematic review suggests that xylitol reduces the amount of S. mutans bacteria in the mouth, which reduces the amount of plaque and may help prevent tooth decay.

A 2014 study examined it on Porphyromonas gingivalis, which is the bacterium responsible for gingivitis, or gum disease. If left untreated, excess amounts of P. gingivalis can move into the bloodstream and lead to systemic inflammation.

In the study, scientists grew samples of P. gingivalis in a laboratory and added them to human cell cultures pretreated with xylitol. They saw that xylitol increased the production of immune system proteins and inhibited the growth of the bacteria.

Ear infections

Xylitol may help prevent ear infections.
Xylitol may help prevent ear infections.

The bacteria that cause tooth plaque can also accumulate behind the eardrum and cause infections of the middle ear. Doctors call these infections acute otitis media (AOM).

A 2016 systematic review found moderate-quality evidence that chewing gum, lozenges, or syrup containing xylitol can reduce the occurrence of AOM from 30 to 22 percent among healthy children.

However, a 2014 study found xylitol syrup to be ineffective in reducing AOM in children at high risk of the infection.

These conflicting results indicate the need for more research regarding the use of xylitol as a preventive treatment for ear infections in children.

Antioxidant properties

According to the National Center for Complementary and Integrative Health, free radicals cause oxidative stress, which can lead to cell damage and may play a role in the development of several conditions, including diabetes, cardiovascular disease, and cancer. Laboratory studies show that antioxidants neutralize free radicals and counteract oxidative stress.

A 2014 study revealed that xylitol may have antioxidant properties. Diabetic rats who ate xylitol produced higher amounts of glutathione. This is an antioxidant that counteracts the harmful effects of free radicals. It is important to note that human studies are needed to validate these findings.

Side effects and safety

The United States Food and Drug Administration (FDA) has approved xylitol as a food additive. It is generally safe, but like other sugar alcohols, it can cause digestive issues such as bloating and diarrhea in some people.

It is worth noting that this substance can be very toxic to dogs. It is vital to store products containing xylitol in a safe place that pets cannot reach. Anyone who thinks that their dog has consumed xylitol should call their veterinarian or the Animal Poison Control Center immediately.

Drug interactions

Currently, xylitol has no known interactions with prescription or over-the-counter medications. Always consult a doctor about potential interactions when starting new medications or supplements, however.

Dosage

The suitable dosage of xylitol can vary from person to person. A 2016 review found that adults can safely tolerate between 10 grams (g) and 30 g  per day, which they usually divide into several smaller doses. After the body adapts, adults can consume up to 70 g per day without side effects.

Studies in children have used doses of up to 45 g daily. Some research suggests that consuming around 5–6 g  per day may help reduce plaque-causing bacteria in the mouth.

However, the American Academy of Pediatric Dentistry says that more research is necessary before recommending xylitol to improve dental health in children.

Alternatives to xylitol

Syrup or nectar in a glass bowl
Agave nectar is an alternative sweetener

Manufacturers use a range of low-calorie artificial sweeteners and sugar substitutes to sweeten foods and beverages. Many of these substitutes are also available as table-top sweeteners, and some people use them in baking.

Some substitutes are significantly sweeter than table sugar. However, its sweetness is very similar to that of table sugar.

Other artificial sweeteners and sugar substitutes include:

Sorbitol

Sorbitol is a sugar alcohol with a similar molecular structure to xylitol. Sorbitol does not spike blood glucose levels, so it is a good sugar substitute for people who have diabetes.

Like xylitol, bacteria cannot break down sorbitol into the acids that cause tooth decay.

Erythritol

Erythritol is another sugar alcohol. Similarly to xylitol, erythritol also inhibits the growth of S. mutans.

A 2016 review found that high concentrations of erythritol are more effective at reducing oral plaque than both xylitol and sorbitol. However, xylitol is more effective than erythritol at lower concentrations.

Stevia

Stevia is a natural sweetener that manufacturers extract from the stevia plant. Stevia extract is available in granular and liquid forms. Purified leaf extract is 250–300 times sweeter than sugar.

Like xylitol, stevia can sometimes cause diarrhea and other digestive issues.

Agave nectar

Agave nectar is a syrup that manufacturers extract from the agave plant and use as a sugar substitute in some drinks and foods.

However, agave nectar mainly contains fructose, which bacteria in the mouth can break down into the acids that cause tooth decay.

Summary

Xylitol is a reduced-calorie sugar substitute similar in sweetness to table sugar. It also has a low GI, which makes it an attractive alternative to sugar for people wishing to lose weight and those with diabetes.

Some research also suggests that this compound has antibacterial properties that can help prevent tooth decay, gum disease, and ear infections. However, further research into the potential health benefits of xylitol is needed.

Single workout metabolic benefits

A single workout offers lasting metabolic benefits.  New research in mice finds that a single workout activates a brain circuit associated with a lower appetite, lower blood sugar levels, and better metabolism. Moreover, this effect lasted for 2 days after the workout. The findings may help improve blood sugar metabolism in people with diabetes.

Single workout boxing routine
A single workout can offer long-lasting metabolic benefits.

According to the most recent estimates from the Centers for Disease Control and Prevention (CDC), more than 100 million people in the United States are currently living with diabetes or pre-diabetes.

In excess of 30 million U.S. adults have diabetes, and more than 84 million have pre-diabetes. According to the CDC, pre-diabetes can evolve into diabetes within 5 years.

Controlling blood sugar levels with physical activity and diet is the key to managing or preventing diabetes. However, new research suggests that we may need less physical activity than we might think to achieve these health benefits. This means that the effects of a single workout appear to offer great benefits to the individual.

Dr. Kevin Williams, a neuroscientist at the University of Texas Southwestern in Dallas, is the corresponding and last author of the new study. Dr. Williams and colleagues examined the effects of a single bout of exercise on two types of neurons in mice.

The neurons make up the so-called melanocortin brain circuit, which humans share with rodents.

Scientists have linked POMC neurons with a lower appetite, reduced blood sugar levels, and a more active metabolism. NPY/AgRP neurons, on the other hand, have an association with an increase in appetite and a slower metabolism.

Dr. Williams and colleagues published their findings in the journal Molecular Metabolism.

How exercise improves glucose metabolism

Scientists have previously studied the properties of the melanocortin brain circuit in relation to diet and fasting, but they have not investigated how physical exercise affects these neurons.

So, Dr. Williams and team examined the brain activity and neuronal firing rate in transgenic mice after a workout consisting of three, consecutive, 20-minute sessions of treadmill running.

They found that the single bout of exercise activated rodents’ POMC neurons, but deactivated the appetite-boosting NPY/AgRP neurons. The scientists noticed these neuronal changes lasted for up to 2 days.

“It doesn’t take much exercise to alter the activity of these neurons,” explains Dr. Williams. The researchers also trained the mice for periods ranging from zero to 10 days and found that the neuronal effects lasted longer if the training period was longer.

Finally, the metabolism-boosting POMC neurons stayed active for longer if they also expressed leptin receptors. Leptin is a metabolic hormone that previous research has shown is of benefit to the synapses of POMC neurons.

Based on our results, we would predict that getting out and exercising even once in a semi-intense manner can reap benefits that can last for days, in particular with respect to glucose metabolism.”

Dr. Kevin Williams

Single workout findings may benefit people with diabetes

The rodents also lost their appetite after the workout. This effect lasted for up to 6 hours after working out. Dr. Williams comments, “This result may explain at the neural circuit level why many people don’t feel hungry immediately after exercise.”

Dr. Williams continues to comment on the benefits of the findings for metabolic conditions. “This research is not just for improving fitness,” he says, adding, “A better understanding of neural links to exercise can potentially help a number of conditions affected by glucose regulation.”

It is possible that activating melanocortin neurons may hold therapeutic benefits for patients one day, especially for [people with diabetes] who need improved blood-glucose regulation.”

Dr. Kevin Williams

 

 

 

 

 

 

 

Applying this concept is essential in establishing an effective weekly workout routine.  No matter which time of the day you prefer to workout, this research clearly points out that the effects of a single workout lasts for two days.  Establishing proper rest time between workouts therefore goes a long way in taking advantage of the long-lasting effects of the single workout.

When properly spaced, the body reacts in a positive way and metabolic systems adjust accordingly.  It does not matter if you are trying to control diabetes, the point is that those who do not suffer from this malady can keep it at bay by being conscientious that the single workout concept does work and the research posted here proves it!

Natural colon cleansing

This post explores the concept of natural colon cleansing. A colon cleanse is a popular alternative remedy that some people claim removes waste and toxins from the colon. However, there is little scientific evidence to support the use of natural colon cleansing routines, except for those that doctors prescribe.

Most of what researchers know about safe colon cleansing comes from studies that aim to find ways to improve the colonoscopy procedure rather than to boost energy levels or treat intestinal problems.

People may refer to colon cleansing methods by different names, including:

  • bowel cleanses
  • detoxes
  • flushes
  • juice diets

Most colon cleansing products supposedly help detox the colon or remove harmful substances, such as mucus and dry stool. Some people also use colon cleanses to help relieve constipation.

In this article, we discuss some popular colon cleansing methods and the science behind them. We also consider their potential benefits and risks.

Water

Woman drinking water as part of natural colon cleanseDrinking water regularly can naturally cleanse the colon.

Using water is one of the easiest and safest natural colon cleansing available, and the easiest way to cleanse the colon naturally. Water moistens stool and gives it bulk, facilitating its passage through the colon.

A person who is dehydrated will have fewer bowel movements because their body is trying to retain water. It will reabsorb water from the bowel, which results in the stool becoming dry, hard, and difficult to pass.

Everyone’s daily hydration needs are different, but it is vital to drink plenty of water throughout the day.

Other beverages, including caffeinated ones, contribute toward a person’s daily water intake, but plain water is the best option as it does not contain any calories.

In a 2013 study, researchers in Jordan found that drinking more than four cups of water daily decreased the risk of colorectal cancer, but the results were not statistically significant.

The same study identified constipation as a significant risk factor for colorectal cancer. Drinking at least eight glasses of water a day can help prevent constipation, and it offers many other health benefits too.

Fruit and vegetable juice

Raw fruit and vegetable juices contain many elements that may help cleanse the colon, including fiber, phytochemicals (beneficial plant chemicals), and natural sugars that act as laxatives, such as sorbitol and fructose.

Proponents of juice cleanses recommend the following types of juice:

  • apple, including the peel
  • prune
  • pear
  • banana
  • kiwi
  • grape
  • plum
  • persimmon
  • lemon

Some colon cleanse plans recommend consuming only fluids for a few days at a time to help cleanse the colon and digestive tract.

Most health authorities recommend against juice cleanses. Raw fruit juices can contain compounds that are hard on the kidneys and liver. Without any treatment to kill harmful bacteria and viruses, these juices can also make people ill. They may pose significant dangers for those with medical conditions, such as diabetes.

It is best to consume fruit and vegetable juices in the form of smoothies to keep all the fiber, water, and nutrients intact.

Fiber

Natural colon cleansing found in fiber adds bulk to stool, which reduces the time it spends sitting in the colon and increases the number of bowel movements that a person has. Many natural, whole foods are rich in fiber, including:

  • nuts
  • beans
  • seeds
  • berries
  • whole grains and cereals

People who find it difficult to get enough fiber through their diet can try taking fiber supplements. Popular fiber supplements include:

  • psyllium (Metamucil)
  • polycarbophil tablets (FiberCon)
  • methylcellulose

Fermented foods aid natural colon cleansing

Baked tempeh on tray
Tempeh is a fermented food that may benefit gut health.

Fermented foods often contain high levels of probiotics, which are beneficial bacteria that contribute to gut health.

These bacteria help the bowels move stool out of the colon regularly and reduce the risk of gas, bloating, constipation, and infection.

Common fermented foods that contain probiotics include:

  • yogurt and Greek yogurt
  • apple cider vinegar
  • kefir
  • skyr
  • kimchi
  • sauerkraut
  • pickles
  • miso
  • tempeh
  • kombucha
  • beer and cider
  • some types of cheese

Research suggests that probiotics may help prevent and possibly treat colon cancer, but researchers agree that more studies are necessary to understand these effects. A healthy gut biome offers numerous other benefits for overall health and immune function.

Resistant starches

Some foods contain resistant starches, which are types of sugar that are difficult for the body to break down. These starches remain mostly undigested and become bulk in the stool.

The more bulk there is in the stool, the sooner the bowel is stimulated into action, possibly helping cleanse the colon.

Foods high in resistant starches include:

  • potatoes, sweet potatoes, and yams
  • sugar beets
  • sugar cane
  • sweet corn
  • green bananas
  • beer and cider
  • vegetable stems, tubers, and roots
  • rice
  • buckwheat and millet
  • al dente pasta
  • white bread
  • cornflakes and muesli

Unlike other starches, digesting resistant starches produces compounds that research shows may help:

  • prevent colon cancer
  • improve macronutrient regulation
  • alter hormone levels, potentially improving mental and physical health
  • prevent or control diabetes
  • prevent or control obesity

Lemon juice

Regularly drinking lemon juice can have a positive effect on digestive health and help natural colon cleansing. It seems that people experience the most benefit when they drink it on an empty stomach, which allows the compounds in the lemon to interact more easily with the gut mucosa.

Having a clean colon is crucial for certain screening tests, such as colonoscopies. Most people receiving colonoscopies have to consume a colon cleansing preparation the night before the procedure.

In a 2015 study on colonoscopies, one group of participants received a preparation of ascorbic acid, or vitamin C, in addition to the standard fluid mixture of polyethylene glycol (PEG). The participants who took vitamin C had better bowel preparation than those in the other groups.

Lemon juice is very high in vitamin C so it may be an effective natural colon cleanser.

Herbal teas

Some herbal teas used in natural colon cleansing may be beneficial for digestive health.

Australian research from 2014 found an association between herbal tea consumption and a lower risk of colon cancer.

Other natural teas, such as ginger or lemon tea, may also help digestion.

Possible benefits of colon cleanses

Senior couple smiling outdoors jogging.
People who support colon cleanses claim they can improve energy levels, though there is no scientific evidence to prove this.

There are currently no proven benefits of colon cleanses, natural or otherwise. However, people who promote colon cleanses claim that they provide major health benefits, including:

  • increasing energy
  • removing toxins
  • improving liver function
  • boosting the immune system
  • aiding weight loss
  • relieving bloating, cramps, and gas
  • reducing the risk of colon cancer
  • improving mood

Safety and risks

Some of the potential risks of colon cleansing include:

  • weakness
  • irritability
  • electrolyte imbalance and dehydration
  • vomiting and nausea
  • abdominal cramps
  • dizziness and fainting
  • loss of healthful gut microflora and increased risk of infection
  • diarrhea
  • bowel ulcerations, which are open cuts and sores
  • bowel infection
  • kidney damage and failure

People with preexisting bowel conditions should avoid bowel cleansing methods unless a doctor performs or prescribes them.

The United States Food and Drug Administration (FDA) do not regulate natural colon cleanse products. The FDA have also taken legal action against companies who were using unproven medical claims to promote cleanse products, stating that they could reduce the risk of cancer or treat serious medical conditions.

The U.S. National Institutes of Health also point out several possible risks of cleanses, including:

  • diarrhea, which could lead to dehydration
  • bacterial infection from unpasteurized juice
  • lack of nutrients
  • headaches
  • weakness and fainting

People with kidney conditions should avoid drinking large quantities of juice because it can contain too much oxalate, which can cause kidney problems.

People with diabetes and other metabolic conditions should also avoid detoxes or extreme diets and instead follow a healthful, doctor-recommended diet.

Severely restricting calorie intake, which is often part of colon cleanses, can also be damaging to a person’s overall health. It rarely contributes to long-term weight loss or well-being.

 

Obesity versus Depression

Is depression the cause of obesity or is obesity the cause of depression? Although depression and obesity often come hand in hand, the relationship between the two is difficult to tease apart. A new, large-scale genomic study adds new evidence.

Pensive woman ponders obesity
The relationship between depression and obesity is complex.

Both excessive weight and depression are significant global health problems. According to the authors of the latest research, they cost the global economy trillions of dollars every year.

Previous studies have noted that depression often appears in individuals who are overweight or obese.

However, observational studies have not been able to demonstrate whether obesity causes depression, as there are many competing factors to consider.

For instance, being grossly overweight is a risk factor for a number of conditions, and so it might be that dealing with other health issues increases the likelihood of becoming depressed, rather than the obesity being the cause.

Some researchers have argued that the relationship might be the other way around: depression is a risk for obesity.

Others believe that depression and obesity exacerbate each other. For instance, obesity might make depression more likely to occur initially, but once depressive symptoms arise, they might compound the condition by making it harder for the individual to exercise. In these cases motivation of the individual would be a great place to start.

Obesity and depression revisited

To gain a better understanding of this complicated relationship, researchers from the University of Exeter in the United Kingdom joined forces with scientists from the University of South Australia. They published their results in the International Journal of Epidemiology this week.

“Obesity and depression are both global health problems that have a major impact on lives and are costly to health services,” explains lead author Dr. Jess Tyrrell. “We’ve long known there’s a link between the two, yet it’s unclear whether obesity causes depression or vice versa, and also whether it’s being overweight in itself or the associated health problems that can cause depression.”

The study used genetic data to inspect the causal relationship between excessive weight and depression. The team wanted to understand whether a higher body mass index (BMI) was related to an increased risk of depression without the presence of other health conditions.

The researchers used genetic and medical data from 48,000 people with depression and compared it with in excess of 290,000 controls, making it the largest study to address this question to date.

Psychological impact to blame?

Overall, as expected, a higher BMI was associated with higher odds of depression. This association was stronger in women than men, confirming earlier findings. Women with a high BMI had a 21 percent increase in risk, compared with 8 percent in men.

By investigating individuals with genes predisposing them to obesity but without ones that predispose them to metabolic conditions, such as diabetes — referred to as a “favorable metabolic profile” — the researchers could separate out the psychological component of obesity.

In their analysis, they accounted for a range of variables that could influence the results, including socioeconomic position, alcohol consumption, smoking, and physical activity.

They found that individuals with a favorable metabolic profile were just as likely to develop depression as individuals with obesity that carried genes predisposing them to develop metabolic conditions. This effect was most pronounced in women.

To double-check their findings, they also took data from the Psychiatric Genomics Consortium. And their second analysis returned similar results, adding further weight to their conclusions.

“Our robust genetic analysis concludes that the psychological impact of being obese is likely to cause depression.” Dr. Jess Tyrrell

These results provide vital insight, as Dr. Tyrrell explains, “This is important to help target efforts to reduce depression, which makes it much harder for people to adopt [healthful] lifestyle habits.”

However, the relationship between the two is convoluted, and questions remain. As the authors write, “we have not ruled [out] a possible bidirectional causal relationship between higher BMI and depression […] Further research is required to explore the causal role of depression on body mass index and obesity.”

Because depression and obesity can have profound impacts on individuals and society at large, scientific attention is likely to continue to look at their links.

Body Mass Index Measurement

This post deals with measuring Body Mass Index (BMI) for adults, children, and teens. Body mass index, or BMI, is a measure of body size. It combines a person’s weight with their height. The results of a BMI measurement can give an idea about whether a person has the correct weight for their height. 

BMI (Body Mass Index) is a screening tool that can indicate whether a person is underweight or if they have a healthy weight, excess weight, or obesity. If a person’s Body Mass Index is outside of the healthy range, their health risks may increase significantly.

Carrying too much weight can lead to a variety of health conditions, such as type 2 diabetes, high blood pressure, and cardiovascular problems.  In a previous post, we offered five simple exercises which can help a person achieve some of their weight goals.

A weigh that is too low can increase the risk of malnutrition, osteoporosis, and anemia. The doctor will make suitable recommendations.

Body Mass Index does not measure body fat directly, and it does not account for age, sex, ethnicity, or muscle mass in adults.

However, it uses standard weight status categories that can help doctors to track weight status across populations and identify potential issues in individuals.

BMI (Body Mass Index) in adults

Body Mass Index calculator shows healthy weight
A BMI chart or calculator can show a person if they have a healthy weight.

Calculating BMI involves measuring a person’s height and body weight.

 

Metric

  • To calculate BMI in metric units, use the following method: BMI = kg/m2
  • So, to calculate an adult’s BMI: Divide their weight in kilograms (kg) by the square of their height in meters (m2)

Since most people measure height in centimeters (cm), divide height in cm by 100 to get height in meters.

Imperial

  • When using imperial units, the formula is: BMI = lbs x 703/in2
  • In other words: Multiply a person’s weight in pounds (lbs) by 703. Then divide by their height in inches, squared (in2)

To avoid using the math, a person can use a calculator or a chart to find their BMI.

BMI calculator

Enter height or weight in either imperial or metric measurements to find your BMI.

1) Metric BMI Calculator

2) Imperial BMI Calculator

BMI charts

People can also work out their BMI using a chart. Click here to see a chart provided by the National Heart, Lung, and Blood Institute (NHLBI).

Locate your height in inches on the side of the chart, then look across to find your body weight in pounds. Scan to the top to see if the result corresponds to a normal weight, overweight, or obesity.

Understanding the results

The following table shows the standard weight status categories associated with BMI ranges for adults.

BMI Weight status
Below 18.5 Underweight
18.5–24.9 Healthy
25.0–29.9 Overweight
30.0 and above Obese

BMI of less than 18.5

A BMI of less than 18.5 indicates that you are underweight, so you may need to put on some weight. You are recommended to ask your doctor or a dietitian for advice.

BMI of 18.5–24.9

A BMI of 18.5-24.9 indicates that you are at a healthy weight for your height. By maintaining a healthy weight, you lower your risk of developing serious health problems.

BMI of 25–29.9

A BMI of 25-29.9 indicates that you are slightly overweight. You may be advised to lose some weight for health reasons. You are recommended to talk to your doctor or a dietitian for advice.

BMI of over 30

A BMI of over 30 indicates that you are heavily overweight. Your health may be at risk if you do not lose weight. You are recommended to talk to your doctor or a dietitian for advice.

BMI in children and teens

In adults, BMI values are not linked to age and are the same for both sexes.

However, measuring Body Mass Index in children and teens is slightly different. Girls and boys develop at different rates and have different amounts of body fat at different ages. For this reason, BMI measurements during childhood and adolescence take age and sex into consideration.

Doctors and other health professionals do not categorize children by healthy weight ranges because:

  • they change with each month of age
  • male and female body types change at different rates
  • they change as the child grows taller

Doctors calculate BMI for children and teens in the same way as they do for adults, by measuring height and weight. Then they locate the BMI number and person’s age on a sex-specific BMI-for-age chart. This will indicate whether the child is within a healthy range.

Calculator and charts for child and teen Body Mass Index

The Centers for Disease Control and Prevention (CDC) have produced a calculator that provides BMI and the corresponding BMI-for-age percentile on a CDC growth chart for children and teens.

First, click here for the calculator.

Next, use the charts to see if a child’s weight is suitable for their age.

Click here for the charts:

What do the results mean?

The following categories explain the meaning of the results:

Weight status category Percentile range
Underweight Below the 5th percentile
Healthy weight 5th percentile to less than the 85th percentile
Overweight 85th to less than the 95th percentile
Obesity Equal to or greater than the 95th percentile

How doctors use BMI

BMI is not accurate enough to use as a diagnostic tool, but it can screen for potential weight problems in adults and children.

If someone has a high or low BMI, a doctor or other healthcare professional might then consider other factors, such as:

  • skinfold thickness measurements, which indicate how much fat is in the body in adults and children
  • evaluations of diet and physical activity
  • discuss any family history of cardiovascular disease and other health problems
  • recommend other appropriate health screenings

The doctor or healthcare professional can then make diet and exercise recommendations based on these results.

Health risks of extra weight

Excess weight has the following effects on the body:

  • It increases how hard the heart has to work.
  • It raises blood pressure, blood cholesterol and triglyceride levels.
  • It lowers high-density lipoprotein (HDL), or good cholesterol levels.
  • It can make diabetes and other health problems more likely.

According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), carrying extra weight can increase the risk of the following conditions:

  • hypertension, or high blood pressure
  • dyslipidemia, which involves high LDL cholesterol, low HDL cholesterol, or high levels of triglycerides
  • type 2 diabetes
  • coronary heart disease
  • stroke
  • gallbladder disease
  • osteoarthritis
  • sleep apnea and respiratory problems
  • some cancers, including endometrial, breast and colon cancer

Carrying extra weight as a child or teenager can also pose significant health risks, both during childhood and into adulthood.

As with adult obesity, childhood obesity increases the risk of various health problems, including cardiovascular disease, diabetes, and sleep apnea.

The American Heart Association (AHA), point out that children with a high BMI also have a higher risk of:

Benefits of a healthy weight

Walking with the family helps Body Mass Index levels
Walking with family or friends can be an enjoyable way of keeping fit and preventing unwanted weight gain.

Apart from reducing the risk of the health conditions, maintaining a healthy weight offers additional benefits:

  • fewer joint and muscle pains
  • increased energy and ability to join in more activities
  • improved regulation of bodily fluids and blood pressure
  • reduced burden on the heart and circulatory system
  • improved sleep patterns

Other measures of a healthy body

BMI is a useful tool, but it cannot identify whether a person’s weight is made up of muscle or fat.

For example, an athlete with a lot of muscle tissue may have a higher BMI than a person who is not very active. But, this does not mean that the athlete is overweight or unhealthy.

In addition, cardiovascular disease and high blood pressure are more likely to occur in people who have additional fat — known as visceral fat — around their middle rather than their hips.

Other measures of body size include waist-hip ratio, waist-to-height ratio, and body composition, which measures body fat and lean body mass. These measurement systems focus more on the amount of fat a person has and its distribution around the body.

Together with BMI, these additional measures can help to assess more accurately the health risks associated with an individual’s weight.

Takeaway

Body Mass Index can be a useful screening tool for predicting certain health risks. However, people should use it with caution, as it does not take other factors — such as activity levels and body composition — into account.

For children and teens, it is important to include their age and sex when taking a BMI measurement, because their bodies continuously change as they develop.