When it comes to diet and weight loss, compared to carbs and fat, protein seems to be on the winning side. However, protein is a source of calories, and eating an excessive amount of calories from protein, or any other macronutrient, can lead to unwanted weight gain. If you're concerned about your weight, consult your doctor to help you design a diet plan that fits your needs.
Protein Calories and Unwanted Weight
Protein is essential for good health. It helps build muscle, repair tissue, support immune health and make hormones and enzymes. However, you only need a set amount of protein to maintain your tissues, and any excess protein in your diet gets used for energy. This is fine if you're not eating too many calories and not gaining weight. But if you're eating large amounts of protein and exceeding your calorie needs because of this protein, that excess protein is converted into unwanted fat weight, just like any other excess calories.
Dangers of Excess Protein
In addition to weight gain, there are other potential dangers of getting too much protein in your diet. These dangers are most often associated with people who take protein powders or amino acid supplements, says the American Council on Exercise. Getting too much protein ups your risk for dehydration if you're not drinking enough water, because protein requires water for metabolism and excretion. Your body also has a hard time processing excess amounts of protein, defined as more than 35 percent of calories from protein, according to a study published in the "International Journal of Sport Nutrition and Exercise Metabolism" in 2006. If you're exceeding this intake limit, the extra protein causes elevated amino acid and ammonia levels, as well as nausea and diarrhea. In some cases, excessive protein intake may even be fatal.
Dietary Protein Needs
The 2010 Dietary Guidelines for Americans says a healthy diet should include 10 to 35 percent of calories from protein. This allows for a significant range for protein in the diet. For example, on a 2,000-calorie diet your protein intake may range from 50 grams to 175 grams a day. Most people only need 0.4 grams of protein per pound of body weight, or 72 grams for a 180-pound person. But if you're working out, you may need as much as 0.5 to 0.7 grams per pound of body weight, or 90 to126 grams for a 180-pound person, to help repair and build muscle.
Protein and Weight Loss
If you're trying to lose weight, getting a little more protein in your diet may help, as long as your staying within your weight-loss calorie range. A 2008 report published in the "American Journal of Clinical Nutrition" reports that protein is more satiating than carbs or fat, and helps you stay full longer so you eat less. Upping the protein in your diet while you're trying to lose weight may also help prevent muscle loss, say the authors of the report. Muscle helps boost your metabolism, and preserving your muscle may help prevent a dip in calorie-burning.
Healthy Sources of Protein
Protein is found in a variety of foods, not just steak. If you're trying to prevent weight gain, you want to include lean sources of protein in your diet. This includes lean red meat such as sirloin or pork loin, poultry, eggs, seafood, and soy products. Grains, vegetables and beans are also a source of protein, although most plant-based proteins fall short in one or more amino acids. However, if you eat a variety of foods throughout the day, you should be able to get all of the essential amino acids your body needs to function normally.
- McKinley Health Center: Macronutrients: The Importance of Carbohydrates, Protein and Fat
- American Council on Exercise: Are There Health Risks Concerning Eating Too Much Protein?
- The American Journal of Clinical Nutrition: Protein, Weight Management and Satiety
- International Journal of Sport Nutrition and Exercise Metabolism: A Review of Issues of Dietary Protein Intake in Humans
- U.S. Department of Agriculture and U.S. Department of Health and Human Services: Dietary Guidelines for Americans, 2010
- Today's Dietitian: Athletes and Protein Intake
- McKinley Health Center: Breaking Down Your Metabolism