A BMI of less than 18.5 kg/m2 indicates you are underweight. You may need to gain weight. If your BMI is 19 to 24.9 kg/m2, you're are a healthy weight, and should aim to stay that way. A BMI of over 30 kg/m2 is defined as obese and means your health is at risk.
What is a normal body mass index?
The body mass index (BMI) or Quetelet index is a value derived from the mass (weight) and height of an individual. Commonly accepted BMI ranges are underweight: under 18.5 kg/m2, normal weight: 18.5 to 25, overweight: 25 to 30, obese: over 30.
What should your body mass index be?
People with a BMI of less than 18.5 are underweight. A BMI of between 18.5 and 25 is ideal. Somebody with a BMI between 25 and 30 is classed as overweight. A person with a BMI over 30 is obese.
The definition of optimum is most favourable. A person's favourable optimum weight could be with reference to general lifestyle or a specific sport. Most sportspeople get to know the weight at which they perform best and make sure they stay as near to it as they can. Optimum weight can be found using BMI index.
Many factors affect optimum weight, such as:
- Bone structure.
- Muscle girth.
Other symptoms of being underweight may include:
- Fragile bones.
- Irregular menstrual periods or problems getting pregnant.
- Hair loss.
- Weak immune system.
- Dizziness or fatigue from anemia.
- Poor growth and development, especially in children who are underweight.
BMI is a number that is used to evaluate your body size. It is not a percentage of body fat, but rather a general score that helps determine if your weight falls into a healthy range.
For example, body fat contains approximately 10 percent water, while muscle is approximately 75 percent water. In general, men should have a total body water percentage between 50 and 65 percent, while the ideal range for women is between 45 and 60 percent.
BMI as a Measure of Body Fat. Body mass index is an easy and inexpensive way to estimate whether someone is at a healthy weight for her height, but it doesn't measure body fat directly. Those with a BMI of 25 or higher are considered overweight, and those who have a BMI of less than 18.5 are considered underweight.
In one month you can reasonably anticipate losing eight to 10 pounds if you follow a pretty strict plan. Losing one pound of body fat is equivalent to 3,500 calories. To lose two pounds per week, you must drop 1,000 calories per day.
Body Fat Percentage Men 10-12% This is a sustainable level for most men where you should be able to see your abs, but they will likely not be as defined as a man in the 6-7% body fat range. This body fat range is the classic beach body look that most men want and many women love.
The American Council on Exercise says, if you follow a healthy dietary and exercise routine, you can expect to lose body fat at a healthy 1 percent per month. At this rate, most people may achieve six-pack abs in anywhere from three to 20 months, depending on your current body fat level.
Typical body fat amounts
If you carry more than 30 percent fat, you are subject to health risks. A 50-year-old female athlete may fall between 14 and 20 percent fat; a fit 50-year-old woman falls into the 21 to 24 percent range; and average women are in the 25 to 31 percent range.
Make sure to note the difference in the two men, both at 10% body fat further down the page. 2) Body Fat Calipers – Pick up a set of calipers for $5. Pull the fat away from your muscles, pinch them with the caliper, take the measurements, and look at a chart to figure out your body fat percentage.
Track Your Body Weight Accurately
- Get yourself a good body scale.
- Weigh yourself at least twice a day: when you wake up, before you go to bed, and in the middle of the day (if possible). Ideally, weigh yourself naked.
- Average every weight measurement for the day.
- Take those averages and average them each week.
How to Measure Body Fat Percentage
- Skin Calipers. It might not be St. Patrick's Day, but get ready to be pinched!
- Bioelectrical Impedance.
- Hydrostatic Weighing.
- DEXA (Dual-Energy X-Ray Absorptiometry)
- Air-Displacement Plethysmography.
- 3D Body Scan.
The Gold Standards
- DEXA (Dual-energy X-ray Absorptiometry) Scan. In a DEXA scan, X-ray technology is used to estimate lean tissue, bone, mineral, and fat across regions of the body with amazing accuracy.
- Underwater Weighing.
- Bod Pod (Whole Body Plethysmography)
- Skinfold Measurements.
- Bioelectrical Impedance.
- Bust: Measure all the way around your bust and back on the line of your nipples.
- Chest: Measure directly under your breasts, as high up as possible.
- Waist: Measure at its narrowest point width-wise, usually just above the navel.
- Hips: Measure around the widest part of the hipbones.
A woman's dimensions are often expressed by the circumference around the three inflection points. For example, "36–29–38" in imperial units would mean a 36-inch bust, 29-inch waist and 38-inch hips. A woman's bust measure is a combination of her rib cage and breast size.
For a woman that is 5 ft 4 in, this would imply the measurements of 36-24-36, i.e. 36″ bust, 24″ waist and 36″ hips.
For most adults, an ideal BMI is in the 18.5 to 24.9 range. For children and young people aged 2 to 18, the BMI calculation takes into account age and gender as well as height and weight. between 18.5 and 24.9 – you're in the healthy weight range. between 25 and 29.9 – you're in the overweight range.
If your BMI is less than 18.5, it falls within the underweight range. If your BMI is 18.5 to 24.9, it falls within the normal or Healthy Weight range. If your BMI is 25.0 to 29.9, it falls within the overweight range. If your BMI is 30.0 or higher, it falls within the obese range.