The Top Ten Nutritional Mistakes By Bill Cashell According to the American Council on Exercise, many active people still make mistakes when it comes to nutrition.  Here are the top 10 dietary mistakes: 1  Skipping Breakfast - Studies show that people who eat a good balanced breakfast every day are more successful at controlling their weight.  You body needs energy after several hours with out food.  Skipping breakfast causes your body to store calories and burn them slower. 2  Working out without fuel - Your body will perform better if it is well nourished, which explains why you run out of energy half way through your workout.  The exception to this is shorter aerobic workouts early in the morning, which tend to burn fat quickly. 3  Working out without refueling - You body needs food within 2 hours of a work out to replenish muscle glycogen store and repair muscle tissue damage.  The best bet is a small meal with complex carbs and protein. 4   Replacing meals with energy bars -  Energy bars are  OK for ocasional use but they tend to be very processed and less beneficial than whole foods. 5  Eating too much protein and not enough carbohydrates - Complex carbs are essential for strong workouts.  Stick with healthy choices such as whole -grain breads and cereals, and fruits and vegetables. 6  Trusting the claims of dietary supplements - This is an unregulated industry, and they can create man y claims that are not proven to be true.  Do your research before buying and supplements. 7  Missing the right amount of calories for energy consumed - No matter how you slice it, it still comes down to taking in the same amount or less than you burn up. 8  Assuming exercise means you can eat anything you want - If you are a professional athlete that trains hard for several hours every day, that may be true.  For the rest of us, it means that exercise is as much a means of health as weight control. 9  Drinking inadequate fluids - Dehydration can lead to fatigue, constipation and other problems.  Drink fluids before, during and after workouts.  Remember to include plenty of water and not just sports drinks. 10 Adopting the popular quick-fix diets - There is a new one every month, and they all promise the same thing - quick weight loss.  Usually that is water weight.  Also, rapid weight loss tends to reduce muscle mass and causes your body to slow it's metabolism.  The best solution is exercise and healthy eating for slow body changes.