Ectomorphs are the type of people that naturally have a high metabolism and a lean, low-fat physique. They are one of three somatotypes identified by Dr. William H. Sheldon in the 1940s 1. While ectomorphs may be able to eat the same number of calories as the stouter endomorphs without gaining weight, there is not significant evidence pointing to the need for extra protein in your diet if you are an ectomorph trying to build muscle.

Body Type Research

Researchers have not extensively examined the nutritional needs for muscle building in the different somatotypes, but what research there is does not indicate a different need in protein intake. A 2000 study in the “American Journal of Human Biology” examined 63 men between the ages of 18 and 40 who had different body types and found that all somatotypes had “normal” nutrient intake levels 3. More recently, a 2007 study of women in their late teens and early 20s in Estonia found no considerable protein intake differences between ectomorphs, endomorphs and mesomorphs.

General Protein Recommendations

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In 2007, the World Health Organization completed an extensive review of dietary protein needs in humans 4. After considering various demographics, the WHO determined that consuming 0.83 grams of protein for every kilogram of body weight is enough protein to satisfy the needs of 97.5 percent of the healthy adult population in the world, including ectomorphic body types. In examining the differences between protein intake and body composition, the organization states that each body type may have a maximum lean body mass achievable through optimum nutrition and exercise, but it is difficult to define maximum protein intake in relation to entire lean body mass 4.

Muscle Building Protein

Regardless of your body type, exercising to build muscle may require you to consume a higher than average amount of protein in your diet. If you are building muscle, you may need anywhere from 1.6 grams to 1.7 grams of protein per kilogram of body weight daily, according to registered dietitian Katie James. This amount is equivalent to around 116 grams of protein per day for a 150-pound person.

Excess Protein Consumption

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The likely reason that ectomorphs cannot grow muscle faster by consuming more daily protein is that your body can only utilize so many amino acids from protein at a given time. James states that consuming more protein than you need in an attempt to compensate for your ectomorphic shape may only lead to gaining fat rather than muscle. In the best outcome of eating too much protein, your body will simply break down the excess protein and excrete it through your urine.