A diet, by definition, is a brief and unsustainable restriction of food or calories.
Most popular weight-loss programs recommend very low calorie intake: 800 to 1,200 calories per day or less for women and 1,500 to 1,800 calories per day or less for males.
When you restrict your calories to these extremes, you will lose weight, at least temporarily.
However, there are two fundamental issues with this strategy.
The first is that rigorous low-calorie diets are nearly impossible to stick to for an extended period of time, therefore weight loss is rarely sustained.
According to the National Weight Control Registry, 95 percent of persons who lose weight on traditional diet plans regain it.
The second issue is that most people ignore good training when dieting, thus the majority of the weight they lose is lean body mass rather than fat.
Best-case scenario: A dieter loses weight but ends up looking like a smaller version of themselves; they haven't changed their physique or grown any stronger, healthier, or fitter. If your only concern is losing weight and you don't care where the weight comes from, how long it stays off, or whether you hurt yourself in the process, you may declare, "All diets work."
If you want to lose fat permanently and without losing muscle, it's more accurate to remark, "Diets never work."
Today, there are more diet regimens than ever before, but there is also more obesity than ever before.
Diet advertising abound, boasting that the holy grail of weight loss has been discovered, but the facts don't lie: most people's weight-loss diets don't work—and there are scientific reasons why.
