Does It Matter What You Eat if You Just Count Calories?

"The most important goal for weight loss is to achieve a negative calorie balance. ... The focus is on calories," says Kristin Reimers, Ph.D., in her chapter on nutrition in the National Strength and Conditioning Association's "Essentials of Strength Training and Conditioning." However, Jane E. Brody, health writer for "The New York Times," begs to differ. So is weight loss about calories, or does what you eat really matter? The answer is probably both.

According to Reimers, your body weight is a result of your energy balance, or the number of calories you consume versus those you expend. Your metabolism, or the rate at which you burn calories at rest, plays a significant role in how quickly you burn calories and is determined by your age, sex, body composition and physical activity level. Regardless of the types of food you put in your body, you need to obtain sufficient calories each day to support your energy needs. A positive or negative energy balance of 3,500 calories will ultimately result in a gain or loss of 1 lb. of body fat, Reimers says.

Brody's argument against calorie-counting stems from a study published in June 2011 in "The New England Journal of Medicine." The study, conducted by nutritionists at Harvard University, examined the dietary and lifestyle habits of more than 120,00 U.S. citizens from 1986 to 2006. They concluded that certain foods were more strongly related to weight gain than others. Among the biggest contributors to weight gain were potato chips, potatoes, sugar-sweetened drinks and both unprocessed and processed meats. On the other hand, vegetables, whole grains, fruits, nuts and yogurt were inversely related to weight gain.

Upon investigating the types of foods in the Harvard study, it probably comes as no surprise that the fattier, fried, processed and sugar-added foods contributed to weight gain, while the more commonly-perceived health foods helped people lose weight. However, the keen nutritionist would likely argue that it's not the unhealthy foods themselves that put on the extra weight. Fatty foods like potato chips and red meat naturally contain more calories than whole grains, fruits and vegetables. Overeating foods high in fat is more likely to result in consuming extra calories than foods high in protein or carbohydrates. Potatoes are high in starch, a carbohydrate that is quickly digested and used for energy. As with added sugars, these foods can leave you hungry and craving food shortly after eating.

Vegetables, whole grains and nuts are all high in complex carbohydrates, particularly fiber. Complex carbohydrates can help you feel full longer and limit cravings for more calories. Fruits and vegetables have a low energy density, meaning they contain few calories based on their weight. You can eat more fruit and vegetables, helping you feel full, without piling on unnecessary calories. Researchers speculated that yogurt contains a bacteria that contributes to satiety.

To lose weight, the general rule of thumb is to count calories. You'll lose weight if you ultimately obtain a negative energy balance. However, certain foods can certainly make this process more difficult. Any effective diet or weight-loss program consists of a balanced meal plan and increased physical activity. Make sure to consume 45 to 65 percent of your calories from carbohydrates, 20 to 35 percent from fat and 10 to 35 percent from protein. Consume plenty of fresh fruits and vegetables; avoid processed, fried and sugary foods; and obtain at least 30 minutes of moderately intense cardiovascular exercise each day.