High protein diets consist of at least 20% protein and very high protein diets contain at least 30% protein. To put things into perspective, the average American diet consists of 12–16% protein.

Some nutritionists recommend a high protein diet to help bodybuilders build muscle and lose fat. The science for this is similar to that of low carbohydrate diets. When carbohydrates are severely restricted, the body begins burning its own fat for fuel — a state called ketosis. Ketosis generates weight loss.

The Origin
High protein diets have been popular since the 1960s. Dr. Maxwell Stillman, a physician who worked with overweight people, observed that patients who experienced the quickest weight loss followed a low fat, low carbohydrate diet. He wrote a book called “The Doctor’s Quick weight Loss Diet” which became known as the Stillman Diet.

By the 1990s, a number of spin-off diets began appearing on bestseller lists. The most popular of this new generation of high protein diets has been the Atkins Diet. Others are the Zone Diet, Protein Power, and Dukan.

Affects of Reducing Carbohydrates
Eating large amounts of protein makes you feel full faster and stay full longer. Protein helps control appetite by fighting carbohydrate cravings and assisting with the burning of calories.

Restricting carbohydrates deprives the body of immediately accessible energy, which causes it, instead, to break down fat stores for energy. This induces weight loss. In addition, the body uses more energy to break down protein than to break down easily digestible carbohydrates, so more calories are used during metabolism. This process, where the body uses fat rather than sugar for energy, is called ketosis.

Ketosis results in the production of substances called ketone bodies, which are acidic. If ketone bodies builds up in the blood, especially for diabetics, a potentially serious condition called ketoacidosis can occur. It’s extremely important to drink enough water to reduce the level of ketones in the blood.  The signs and symptoms of ketoacidosis are fruity-smelling breath, loss of appetite, nausea, vomiting and fast, deep breathing.

A high protein diet also espouses a low intake of carbohydrates and sugars, which is beneficial because:

1. If the energy in carbohydrates is not used immediately, the body stores it as fat.

2. Carbohydrates raise blood sugar levels, making it hard to focus. This is known as “brain fog”.

3. Too many carbohydrates are known to induce nervousness and anxiety; when you reduce the intake of sugars, moods  tend to stabilize.

4. Too much sugar encourages “compulsive” or “emotional” eating.

5. Reducing sugar intake is also beneficial for dental health (less dental plaque; improved gum health, fewer cavities).

Food Choices
Choose lean sources of protein like chicken, turkey and fish. Beans, whole grains, nuts and low-fat dairy products are also good sources of non-animal protein. Most protein powders or supplements are made of whey protein. The amount of protein you consume should be related to body mass. Current protein recommendations from the National Institutes of Medicine are 0.8 grams per kg of body weight per day

Sometimes a high protein diet can lead to eating more saturated fat because some  meats like beef and pork are high in both protein and fat. Diets high in saturated fat can lead to an increase in LDL cholesterol, which raises your risk of heart disease, according to the Mayo Clinic. Try to choose lean sources of protein. Plant sources are often leaner.

Advantages of a High Protein Diet

1.  High protein diets result in rapid weight loss. The Stillman Diet claims a person can lose up to 30 lb (13.5 kg) in 28 days.

2.  Protein is important for rebuilding all cells, not just muscle cells. Hair, nails, cartilage, skin, bone and blood cells are also significantly benefited by protein rich foods. Protein is also essential for hormone, enzyme and other important chemical production.

3.  High protein consumption promotes the growth and maintenance of lean muscle mass.

4.  Low carbohydrate and low sugar diets have been linked to improved concentration.

5.  According to Donald Layman, a professor at the University of Illinois, increased protein intake can benefit patients with osteoporosis, type 2 diabetes, metabolic syndrome, heart disease, and sarcopenia, as well as obesity.

6.  A recent study from the University of Copenhagen in Denmark shows that a high protein diet can be beneficial to women with polycystic ovary syndrome (PCOS).

Disadvantages of a High Protein Diet

1.  High protein meat products are often also high in animal fats. Animal fats are mostly saturated fats and cholesterol; and known to increase the risk of heart disease and certain types of cancer.

2.  Fruits and vegetables are a key source of antioxidants and vitamins such as beta-carotene, vitamin C, protective bioflavonoids, and certain minerals. Eliminating vegetables and fruits can therefore put you at risk of vitamin and mineral deficiency.

3.  By eliminating fruits and vegetables, you also cut out a key source of dietary fiber. This can lead to constipation, diverticulitis, irritable bowel syndrome.

4.  High protein diets can cause the body to accumulate ketones, which result in a body odor. To counteract this, make sure to drink lots of water—more than normal—to help dilute the ketones.

5.  Studies have shown that weight loss from high protein diets is not a long-term solution to obesity and its effectiveness is primarily due to water loss.

A high protein diet keeps you full for a long time and is excellent for body building and muscle development, as well as weight loss. However, most high protein diets are also low in carbohydrates and in fruit and vegetables which are important to the body’s health.  Any diet that involves the elimination of large numbers of foods requires careful observation.

Read More:
15 Protein Powerhouse Vegan Foods
Protein-Packed Quinoa Stuffing For Gluten-Free Family Feasts
Protein Pancakes in 10 Minutes