Nutrition for Body Buinding

The high levels of muscle growth and repair achieved by bodybuilders require a specialized diet. Generally speaking, bodybuilders require more calories than the average person of the same weight to support the protein and energy requirements needed to support their training and increase muscle mass. A sub-maintenance level of food energy is combined with cardiovascular exercise to lose body fat in preparation for a contest. The ratios of food energy from carbohydrates, proteins, and fats vary depending on the goals of the bodybuilder.^[8]

Carbohydrates play an important role for bodybuilders. Carbohydrates give the body energy to deal with the rigors of training and recovery. Bodybuilders seek out low-glycemic polysaccharides and other slowly-digesting carbohydrates, which release energy in a more stable fashion than high-glycemic sugars and starches. This is important as high-glycemic carbohydrates cause a sharp insulin response, which places the body in a state where it is likely to store additional food energy as fat rather than muscle, and which can waste energy that should be directed towards muscle growth. However, bodybuilders frequently do ingest some quickly-digesting sugars (often in form of pure dextrose or maltodextrin) after a workout. This may help to replenish glycogen stores within the muscle, and to stimulate muscle protein synthesis.^[9]

Protein is probably one of the most important parts of the diet for the bodybuilder to consider. Functional proteins such as motor proteins which include myosin, kinesin, and dynein generate the forces exerted by contracting muscles. Current advice says that bodybuilders should consume 25-30% of protein per total calorie intake to further their goal of maintaining and improving their body composition.^[10] This is a widely debated topic, with many arguing that 1 gram of protein per pound of body weight is ideal, some suggesting that less is sufficient, while others recommending 1.5, 2, or more.^{[11][12][13][14]} It is believed that protein needs to be consumed frequently throughout the day, especially during/after a workout, and before sleep.^[15] There is also some debate concerning the best type of protein to take. Chicken, beef, pork, fish, eggs and dairy foods are high in protein, as are some nuts, seeds, beans and lentils. Casein or whey are often used to supplement the diet with additional protein. Whey protein is the type of protein contained in many popular brands of protein supplements, and is preferred by many bodybuilders because of its high Biological Value (BV) and quick absorption rates. Bodybuilders usually require higher quality protein with a high BV rather than relying on protein such as soy, which is often avoided due to its claimed estrogenic properties.^[16] Still, some nutrition experts believe that soy, flax seeds and many other plants that contain the weak estrogen-like compounds or phytoestrogens can be used beneficially as phytoestrogens compete with this hormone for receptor sites in the male body and can block its actions. This can also include some inhibition of pituitary functions while stimulating the P450 system (the system that eliminates chemicals, hormones, drugs and metabolic waste product from the body) in the liver to more actively process and excrete excess estrogen.^[17][18]

Bodybuilders usually split their food intake for the day into 5 to 7 meals of roughly equal nutritional content and attempt to eat at regular intervals (normally between 2 and 3 hours). This method purports to serve two purposes: to limit overindulging as well as increasing basal metabolic rate when compared to the traditional 3 meals a day. However, this has been debunked as the most reliable reasearch using whole-body calorimetry and doubly-labeled water finds no metabolic advantage to eating more frequently.^[19][20]