You can lower your body mass index (BMI) by leading a healthy lifestyle. Calories can be lost by switching to a healthy diet. You can avoid ingesting too much fat, which raises your BMI, by creating a calorie deficit, where you consume fewer calories per day than you expend. Lower BMI can be achieved by exercising for at least 30 minutes each day.
What Is A Body Mass Index?
The body-mass index (BMI) is a diagnostic tool for screening that calculates your body fat percentage by dividing your height by your weight. BMI does not alone diagnose health. Healthcare practitioners analyse someone's health state and hazards using BMI as well as other tools and tests. The BMI is commonly used to determine how far an individual's body composition deviates from what is typical for a person's height. Body fat may account for some of the weight surplus or deficit, but other characteristics such as muscularity also have a substantial impact on BMI.
The usual BMI chart should not be used to determine a child's or adolescent's weight. Consult your child's doctor about the ideal weight range for their height and age.
Calculating Your BMI
The recommended BMI for most adults is between 18.5 and 24.9. Among children and adolescents aged 2 to 18, the BMI calculation takes age, gender, height, and weight into account.
|Weight Status||Body Mass Index (BMI)|
|Healthy weight||18.5 - 24.9|
|Overweight||25 - 29.9|
Obesity is commonly classified into subcategories.
|Obesity Class||Body Mass Index (BMI)|
|Class 1||30 - 34.9|
|Class 2||35 - 39.9|
|Class 3||≥ 40|
Adults' BMI is essentially stable regardless of their age unless they acquire or lose a significant amount of weight. When classifying adults' BMI, irrespective of age or gender, the same subcategories can be used to define underweight, overweight, or obesity.
Children's BMI is more difficult to assess than adults' because their BMI changes as they grow. Growth trends vary among boys and girls, thus both a child's age and gender must be considered when determining whether their BMI is too high or too low. Since the link between a child's BMI and the amount of fatness evolves over time, using fixed standards like those used for adults on children would result in misleading results.
Rather than utilising fixed BMI criteria to distinguish adults, children's BMI is classified using variable thresholds that take into account the child's age and gender. These criteria are often calculated from a population recognised as a child growth reference. They are estimated by weighing and measuring a large cohort of adolescents to see how BMI varies throughout the population by age and gender. These statistics not only illustrate the development trend, but also the average BMI for children at a certain age, as well as the dispersion of measures above and below this number. Individual children may be compared to the reference population, and the degree of deviation from a predicted value can be computed. BMI thresholds are typically expressed as a certain centile in a child's growth reference. After calculating a child's BMI centre, the figure may be examined to determine if it is over or below the set criteria for the child's growth reference.
Are BMI Charts Always Accurate?
The vast majority of research demonstrates that a person's risk of developing chronic diseases and passing away before their time increases if their BMI is below 18.5 (underweight) or above 30.0 (obesity).1 According to a study of 16,868 participants, those with an "obese" BMI had a 20% higher chance of dying from any cause including heart disease than those with a "healthy" BMI.2 However, the real health of an individual may be overestimated or underestimated if only BMI is used. Other crucial health parameters, such as insulin, blood glucose, heart rate, blood pressure, and inflammatory levels, may be missed if just BMI is used.
Even while a higher BMI is associated with worse health outcomes, the distribution of body fat may be more important.
People with a pear-shaped body type—those who have fat deposited in their hips, buttocks, and thighs—had a lower chance of developing chronic diseases than people with an apple-shaped body type (fat deposited in the midsection). For instance, researchers discovered that individuals with an apple-shaped fat distribution had a substantially greater risk of all-cause death than those with a pear-shaped fat distribution in an analysis of 72 studies which included data from more than 2.5 million individuals.3 The researchers emphasised that BMI does not take into account where fat is deposited in the body, which can lead to incorrect classification of a person as being unhealthy or at risk of disease.
The health of particular ethnic and cultural groups cannot always be accurately represented by BMI, despite the fact that it is commonly used by all individuals. In contrast to white people, individuals of Asian origin had a higher risk of chronic illness at lower BMI values, according to multiple research.4 Additionally, despite having higher muscle mass and lower fat mass, Black individuals may be mistakenly labelled as overweight. This may imply that Black women, in particular, have a greater BMI cutoff criterion for chronic illness risk than those of other races.5
Utilising BMI alone ignores how important body size is to many groups on a cultural level. Higher fat mass is regarded as desirable and healthier in some cultures. Healthcare providers must take into account cultural differences.
In addition, BMI employs the same formula for both sexes even though men and women have different body compositions, with males having greater muscle mass and far less fat mass than women.6
Benefits Of Having A Healthy Body Weight
By lowering the pressure in the arteries, losing weight can make the heart healthier since the heart won't have to work as hard to pump blood throughout the body.
Improved quality sleep
A problem known as sleep apnea, which is characterised by interrupted breathing while sleeping, is more common among overweight persons. Increased fat deposits in the neck caused by being overweight might block your airways. Losing weight won't likely completely cure sleep apnea in most people. However, the National Sleep Foundation reports that in moderately obese people, decreasing merely 10% to 15% of body weight might enhance sleep quality and lessen the severity of sleep apnea.
Despite the absence of a clear link between losing weight and self-esteem, multiple studies indicate that it can boost confidence and mood. In order to assess the psychological advantages of weight reduction, a 2014 study looked at 36 studies.7 Subjects who lost weight showed consistent alterations in how they felt about their bodies, how valuable they thought they were, and how happy they were in general.
Overall, maintaining a healthy weight helps your body circulate blood more effectively. Your fluid levels are easier to control. Diabetes, heart disease, some malignancies, gallstones, osteoarthritis, breathing issues, and sleep apnea are less likely to occur in you.
Healthy Ways To Lower BMI
Since calories in food may mount up rapidly, cutting back on your calorie intake will help you lose weight. You can avoid consuming too much fat, which raises your BMI, by creating a calorie deficit, where you consume fewer calories per day than you expend. You'll have more energy if you eat more fibre, and it will also help you maintain the proper functioning of your body's systems. Following increased fibre, your BMR (Basal Metabolic Rate), or the number of calories needed to keep your body operating at rest, will rise.8 Additionally, doing this might hasten the process of losing weight. Oatmeal and whole wheat flour are two additional excellent sources of fibre, as are whole grain ingredients and goods.
One of the best methods to deliberately lower your BMI is through exercise. The World Health Organisation advises individuals to engage in at least 30 minutes of moderate aerobic activity five days a week. Every day, kids should try to engage in an hour of physical activity. An excellent example of an aerobic workout that speeds up your heart and breathing is swimming, jogging, and cycling. Anaerobic exercise promotes the growth of muscle mass more than aerobic activity does. Because of this, when you engage in aerobic activity, you burn fat rather than adding a lot of weight to your muscles.
Weightlifting and other resistance exercises like push-ups and ab crunches are examples of anaerobic exercise. Although an increase in muscle mass might cause the scales to read the same weight even when you are actually losing weight through anaerobic activity, you might not notice a short-term decrease in weight. But, as your muscles develop over time, you should start to see a decrease in your weight and, consequently, in your BMI.
Body mass index (BMI) is a gauge of physical size. It incorporates a person's height and weight. The results of a BMI calculation might provide insight into whether a person is at the ideal weight for their height. Healthy BMI ranges are between 18.5 and 24.9. A person's true health may be underestimated if solely their BMI is used as a measure of their health. In individuals with type 2 diabetes, maintaining a healthy body weight enhances insulin sensitivity. Adipose tissue is reduced as a result of weight reduction, which improves the body's control over blood sugar. BMI may be lowered in a variety of ways including exercise and a healthy diet.
- Klatsky A. Body Mass Index and Mortality in a Very Large Cohort: Is It Really Healthier to Be Overweight? The Permanente Journal. 2017;
- Borrell LN, Samuel L. Body Mass Index Categories and Mortality Risk in US Adults: The Effect of Overweight and Obesity on Advancing Death. American Journal of Public Health [Internet]. 2014 Mar 1;104(3):512–9. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3953803/
- Jayedi A, Soltani S, Zargar MS, Khan TA, Shab-Bidar S. Central fatness and risk of all cause mortality: systematic review and dose-response meta-analysis of 72 prospective cohort studies. BMJ. 2020 Sep 23;m3324.
- Zheng W, McLerran DF, Rolland B, Zhang X, Inoue M, Matsuo K, et al. Association between Body-Mass Index and Risk of Death in More Than 1 Million Asians. New England Journal of Medicine [Internet]. 2011 Feb 24 [cited 2019 Apr 16];364(8):719–29. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4008249/
- Rahman M, Berenson AB. Racial difference in lean mass distribution among reproductive-aged women. Ethnicity & disease [Internet]. 2010 [cited 2022 Sep 1];20(4):346–52. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3076634/
- Nuttall FQ. Body Mass Index. Nutrition Today [Internet]. 2015;50(3):117–28. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4890841/
- Lasikiewicz N, Myrissa K, Hoyland A, Lawton CL. Psychological benefits of weight loss following behavioural and/or dietary weight loss interventions. A systematic research review. Appetite. 2014 Jan;72:123–37.
- Solah V, Kerr D, Hunt WJ, Johnson S, Boushey C, Delp E, et al. Effect of Fibre Supplementation on Body Weight and Composition, Frequency of Eating and Dietary Choice in Overweight Individuals. Nutrients [Internet]. 2017 Feb 16 [cited 2019 Oct 21];9(2):149. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5331580/