Editor's note: Manuel Villacorta, MS, RDD, CSSD, is the founder of the interactive weight-management web site Nu4You and the lead nutritionist for RealJock's Weight-Loss Challenge. Want his personal help losing weight? Enter the challenge!
We all have cherished ideas about how to lose weight—but a lot of common notions about weight-loss are more myth than fact. Clinging to those myths can keep you from your goals, or even frustrate you into giving up. I've isolated my top nine myths about diet and exercise. Free your mind and the rest will follow….
Myth 1: Eating fewer carbohydrates burns more fat.
In order to lose fat you must lose weight, and to lose weight you must eat fewer calories than you are expending. But cutting just carbohydrates is not the solution—and may even be part of the problem. Your body needs carbohydrates so that you can function properly and sustain your exercise plan. Plus, carbohydrates actually help you burn fat as you lose weight by transporting fat cells to be metabolized. So, if you are lacking "carbs" you may actually stop burning fat cells. Carbohydrates, such as whole grains, are rich in B vitamins, which are key elements in helping your metabolism work. Thus a diet low in whole grains will actually negatively affect your metabolism. In addition, the two primary sources of energy when you exercise are glucose in the blood (a simple carbohydrate) and glucose in muscle in the form of glycogen (a complex carbohydrate). Therefore, if carbohydrates are either missing from your diet or are being eaten in insufficient amounts, your body will be forced to obtain the glucose needed for energy from protein. Your body gets protein energy by breaking down your muscles, which causes decreased muscle mass and can be very detrimental for the functioning of your body. This is especially bad given that muscle drives your resting metabolic rate, so having a higher muscle mass helps burn more fat, even while you are at rest.
Myth 2: If you begin an exercise program, you will lose fat.
Many people start an exercise program with the dream of losing weight. But exercise should not be used as a sole method for weight loss. You must really look closely at your diet. Eighty percent of the weight-loss game is your nutrition. You can exercise all you want, but you will not see the scale move down unless you eat fewer calories. Many people have signed up for marathons, boot camps, spinning classes, and gyms with the hope of losing weight, only to end up gaining it instead. Certainly, exercise is a great addition to a weight loss plan and will help you maintain muscle and burn calories, but eating the right diet is key.
Myth 3: Sit-ups will enable you to lose fat around the stomach and hips.
No matter what you've heard or hoped for, spot training does not burn fat from specific areas. You can build muscle in specific places, but fat loss happens gradually, throughout your whole body—and different people lose fat in different locations. Fat storage is very individualized. But the muscles do matter: When overall body fat decreases, the muscles you have worked on will become visible.
Myth 4: More exercise equals more weight loss. No pain, no gain!
You have to be careful about involving yourself in an extreme exercise plan because this can actually be a huge barrier to weight loss. It is counter-intuitive, but if you create too much of a caloric deficit with exercise your weight loss could stop, leaving you frustrated and ready to quit. Exercising more means your body needs more fuel—so if you are not fueling properly your metabolism may shut down. You'll go into emergency mode, where your body carefully preserves every calorie it gets.
So follow the plan that your RD has provided and stop thinking "the more the better." To lose weight you do have to burn more calories than you take in—but within reason. If you have found your proper deficit and you are losing weight, then continue with your plan. Don't get greedy—increasing exercise does not always mean weight loss will happen faster.
Myth 5: The more cardio the more fat loss.
You need a combination of cardiovascular exercises and strength training to burn fat and keep it off. Cardiovascular exercises can help you become more cardio fit and create a deficit of calories faster than resistance training, but strength training helps by maintaining muscle mass. Muscle mass is imperative for a strong metabolism, and for keeping your metabolism fast—and that is key to fat loss over time.
Myth 6: Empty stomach workouts burn more fat.
This is an old and insidious myth. Eating before you exercise will help improve performance, therefore giving better results from your exercise plan. On an empty stomach you don't have the energy to push yourself through your workouts and get all you can from them. And, exercising on an empty stomach will leave you feeling tired and sluggish for the rest of the day. There's a simple analogy: Your car will not run without gas just as your body will not run properly without food.
Myth 7: For weight loss you should engage in low-intensity, fat-burning exercises.
Weight loss depends on the total number of calories you burn, not the type of calories you burn. High-intensity exercise burns more calories than low-intensity exercise, thereby creating a higher calorie deficit and promoting greater weight loss. Exercising in the low heart-rate zone may end in frustration—your weight loss will be slower; results are much faster from high-intensity exercises. However, exercising at a lower intensity is better if training for a marathon or distance triathlon, as you need to retain your glycogen storage in order to sustain long periods of exercise.
Myth 8: Muscle weighs more than fat.
This is one of the most widely used aphorisms in the fitness world and it is just plain incorrect. One pound of fat and one pound of muscle both weigh one pound. One pound of feathers and one pound of rocks both weigh one pound. That being said, muscle is denser than fat and takes up less space. One pound of muscle also burns more calories than one pound of fat. Estimates indicate that one pound of muscle burns roughly 50 calories per day, while one pound of fat burns approximately two calories per day.
Thus, while fat and muscle weigh the same, adding extra muscle through exercise can be a powerful tool when it comes weight loss and maintenance.
Myth 9: You can build muscle while losing weight.
Your metabolism has two basic modes: anabolic, which means building-up, or adding; and catabolic, which means breaking-down or eliminating. Losing fat occurs in catabolic mode (which includes maintaining a calorie deficit), while adding muscle requires that you be in anabolic mode (which involves maintaining a small calorie surplus). I usually recommend that you start with aiming to lose fat while preserving existing muscle by consuming proper amounts of protein and strength training as recommended. Then, when fat goals are reached, switch the aim to muscle gain (and weight) while minimizing fat regain.