What happens when you crash diet (about <1000-1200 calories for women and <1600-1800 for men depending on body size)? Does it work? Here’s what’s going on.
1. CRASH DIETS SLOW METABOLISM
Due to hormonal changes your body starts conserving energy, you get hungrier, and your metabolic rate slows down, which means that you require less calories per day. Slower metabolism can continue after the very low calorie diet.1
2. WEIGHT LOSS DOES NOT LAST
Experts believe that a slower metabolism may play a part in why over 80% of conventional dieters and crash dieters unable to maintain weight loss.
Once you stop the diet and start to eat what used to be your normal daily maintenance level of calories, you may gain the weight you lost right back.2
Since your metabolism has slowed down you require fewer calories than before you started the diet. This means that when you eat a normally you gain weight.
3. CRASH DIETS CAUSE MUSCLE LOSS
Research suggests that the body loses a disproportionately high amount of muscle during very low calorie intake and that this may suppress metabolism by up to 45 percent. Muscle is metabolically active, and losing muscle contributes to a slower metabolism.3
Furthermore, often much of the weight lost during crash diets is water, this is especially true for low carbohydrate diets. Once the body gets re-hydrated with water, the weight will come right back.
To lose weight permanently implement healthy lifestyle choices and regular exercise. Research from the National Weight Control Registry, shows that nearly all people who lose weight and keep it off made changes to their diet and exercise on average an hour a day, the most common activity being walking.45