How Does The Body Lose Protein?

Protein deficiency is rare in the United States and developed countries. One of the three primary macronutrients, protein is essential for several functions in your body, including cell growth and repair, muscle growth and healthy immune function and metabolism. However, certain dietary practices and lifestyle habits can cause your body to lose protein, leading to health problems including a greater risk of illness, fatigue and hair loss.

Dieting

Diets that severely restrict calories, such a fad diets or low-calorie diets, often lead to deficiencies in nutrients such as protein. In general, women should consume no fewer than 1,200 calories daily and men should consume no fewer than 1,500 calories when dieting. Low-calorie and very low-calorie diets, which are primarily used to treat obesity, must be medically supervised to ensure that you do not experience nutrient deficiencies and related complications.

Overtraining

Training too often or with too much intensity can also cause your body to lose protein. High-intensity training uses up glycogen stores in muscles quickly. When glycogen levels are low, your liver looks to protein from muscle and other body proteins to make glucose for energy. As a result, athletes require more protein daily than people with lower levels of physical activity in order to repair, grow and maintain lean muscle mass.

Plant-based Diets

If you are a vegetarian or vegan, you're more at risk for losing protein. Plant foods such as fruits, vegetables and nuts are incomplete proteins, which means they do not contain the nine essential amino acids your body needs. Unlike nonessential amino acids, which your body can produce on its own, essential amino acids must come from food. In order to get them from a plant-based diet, you must eat a wide variety of foods including legumes, seeds and whole grains. Also, include soy --- the only complete plant protein --- in your diet.

Inactivity and Illness

Lack of physical activity leads to muscle wasting or atrophy, a condition characterized by increased turnover of protein and amino acids. Illness and being bedridden also cause significant muscle wasting. Increased activity and greater protein consumption can reverse muscle atrophy due to lack of activity when you're ill.

Boosting Protein Intake

In general, women need 46 g of protein daily and men need 56 g, according to Lisa Hark, a registered dietitian and Darwin Deen, a family doctor, who wrote "Nutrition for Life." Lean meat, poultry, fish and animal products such as eggs and milk are excellent sources of protein, giving your body all the amino acids it needs. Always choose low-fat meat protein such as extra lean beef, skinless poultry or fat-free milk. Besides soy, eat a variety of vegetarian sources such as fruits, vegetables, nuts, seeds and whole grains to get all the amino acids necessary.