One important aspect of creating lean muscle mass has to do with levels of two important hormones, testosterone and human growth hormone (hGH), both of which may be influenced by diet.
However both can also be influenced by type of exercise as well. Diet composition and amount of calories can influence testosterone levels. Diets that are higher in protein, cholesterol, saturated fat, and total fat content will help to sustain higher testosterone levels.
One study found that decreasing fat calories from 40% to 25% while decreasing saturated fat and increasing polyunsaturated fats in healthy male subjects led to decreases in both total testosterone of [-18%] and free unbound testosterone levels of [-15%]. Once the 40% fat diet was resumed testosterone levels returned to original values.
In accordance with a decrease in fat the subjects ate 500 fewer calories as well, implying that both fat restriction and caloric restriction may have a negative effect on testosterone levels
- Eating a slightly higher fat diet may not be all that bad, since intense training has been shown to be cardio-protective against diets with moderate amounts of saturated fats and cholesterol. Research also suggests that eating a higher protein diet can support higher testosterone levels, and those who eat more protein typically consume more animal foods that are higher in fat
- However, I would caution against excess in any form and make sure that there are adequate amounts of protein and fat.
Human growth hormone can also influence lean body mass and a deficiency can cause reduced lean body mass and mineral bone density, increased body fat, decreased HDL, increased LDL, reduced renal plasma flow, reduced muscle bulk, decreased exercise performance, reduced extra cellular fluids, increased waist to hip ratio, reduced basal metabolic rate, decreased muscle strength, and reduced anaerobic threshold. Normally as we age hGH levels will decrease, but certain dietary factors can influence either the enhancement or inhibition of hGhH. Fasting, excess sugar and CHO causing increased insulin, and alcohol can also inhibit hGH. While reducing your BMI, increasing protein, fatty acids, niacin, and caffeine have all been shown to enhance hGH production (1,2)....more