You might have heard a pound of fat equates to 3,500 calories. So, theoretically, if you cut 500 calories a day from your typical food intake, you should lose a pound of fat a week, Right? Not always. To the dismay of many dieters, weight loss is not as mathematical as we would like it to be. Here’s why.
When athletes have excess body fat to lose, they tend to lose it relatively easily. Knocking off 500 calories a day can indeed result in a pound of fat loss a week. But when already lean athletes get below their genetic weight, fat loss can slow to a crawl and they can become very frustrated. Athletes might think reducing their calorie intake, even more, would be a good idea, but it’s not.
When you restrict calories, your brain perceives the lack of fuel as famine and it starts to conserve energy. If you add on extra exercise to burn off even more calories, you’ll make the “famine” even worse, especially if your body is already lean and you are just trying to lose those last few pounds. When fuel is scarce, your body conserves energy. You’ll maintain weight at a calorie intake that historically would have resulted in fat loss. You’ll also be depriving your body of nutrients (like protein to build muscles, calcium to strengthen your bones, riboflavin to convert food to energy, etc.). And just as important, you’ll lack the energy you need to perform well. When dieters stop restricting calories and the famine ends, the metabolism will quickly return to normal.
Nature protects the body from losing weight during a (perceived) famine by slowing your calorie-burn: your heart rate slows due to lack of fuel. You feel excessively tired. You can muster up the energy to exercise, but then are droopy the rest of the day. Fatigue becomes your middle name. Blood flow to your hands and feet slows to keep your organs warm. You feel cold all the time. Your intestinal tract slows down and constipation can become an issue. Your hormonal system reverts to pre-adolescence. Females produce less estrogen and can stop having regular menstrual periods. Males produce less testosterone. All of this is unhealthy for a teen athlete.
Role of genetics
When an athlete complains about lack of fat loss despite restricting his or her food intake, one of my first questions is “How do you look compared to others in your genetic family? Are you leaner—or far leaner—than they are?” The standard response is the athlete is far leaner. Remember, the apple doesn’t fall too far from the tree. You were born with a genetic blueprint for your body; your appropriate weight might differ from your dream physique.
To figure out if you are not losing fat because you are getting too lean, pay attention to what others say about your body. Are they concerned? If your parent tells you are too thin, listen up and stop striving to be leaner yet. Being too thin is very hard to maintain. Rather than starve yourself to lose those last few pounds, gently accept your physique and be grateful for what your body does for you. It is vital, healthy, powerful, and able to do what you ask it to do. It allows you to walk, run, and live an active lifestyle. It is the vehicle that carries you through each day.
If you are confused about losing weight and still have the energy needed to exercise well, consider meeting with a sports dietitian (RD CSSD). This nutrition professional can guide you through your weight loss journey. The referral network at www.eatright.org can help you find your local expert.