Body Mass Index (BMI) provides an easy way to measure obesity, but more doctors are questioning its accuracy and usefulness. BMI is supposed to estimate the amount of body fat a person carries based on height and weight, and categorizes people based on what is appropriate for their size. BMI readings under 18.5 mean you are underweight, and could put on a few pounds. If you fall between 18.5 and 24.9, you’re considered normal, while a BMI of 30 or higher qualifies as overweight.
But in recent years, more researchers argue that it’s not the most accurate way to measure body weight. For years, scientists have said that BMI can’t distinguish between fat and muscle, which tends to be heavier and can tip more toned individuals into overweight status, even if their fat levels are low.
About a year ago, a trainer at my local gym explained to me why lifting weights is so important.
He said that a lot of people who come to see him will
- Not lift weights
- Start very restrictive diets
- Inevitably fall off of the strict diets
- Gain the weight back
- Repeat steps 2–4
Problem With Restrictive Diets: This doesn’t seem like a major problem at first. What’s wrong with going through phases of gaining and losing weight if it lets me eat what I want when I’m not ‘dieting’?
Because this hypothetical person isn’t lifting weights, when they lose weight they will also lose a percent of their muscle mass.
Changed Body Composition: Over a long period of time gaining and losing weight eating whatever they want, the same person who was 180 lbs and 15% body fat when they were 20 might become 180 lbs and 30% body fat by the time they’re 40. Even though they weigh the same (and have the same BMI), they have become much less healthy over the 20 years. This is one reason that BMI isn’t a good indicator for health.
Proposed Solution: If you lift weights regularly and can stick to any diet for the long term you won’t fall into this cyclical trap. It sounds intimidating, but take it one day at a time and start slowly. Regularly doesn’t have to be 6 days a week. You can start at 2 or 3 and raise or lower the volume of exercise to fit your schedule, as long as you stay consistent to keep your muscles strong. More muscle -> more calories burned at rest -> more you can eat. The key is to getting to a level of consumption you are comfortable with and finding a diet you like and can stick to long term.
Source: Quora