Nutrition
The U.S. Department of Agriculture recommends a daily protein intake of 0.8 grams per kilogram of body weight. Active people could benefit from up to 1.5 grams of protein per kilogram of body weight.
Jose Antonio and colleagues from Nova Southeastern University in Florida found that a high protein intake (3.4 grams per kilogram of body weight per day) combined with a periodized exercise program with weights over an 8-week period resulted in a greater reduction in body weight, body fat percentage and fat mass than 2.3 grams of protein per kilogram of body weight. There were no differences in fat-free mass.
Previous studies have shown that a very high protein intake without training with weights did not change body composition. The scientists concluded that intensively training athletes would benefit from a protein intake higher than two grams of protein per kilogram of body weight per day.
(Journal International Society Sports Nutrition, 13: 3, 2016)
Carbohydrates are the primary source of energy for muscle training above 65 percent of maximal effort.
Timothy Fairchild and colleagues from Murdoch University in Australia found that consuming glucose (75 grams of glucose) prior to exercise did not improve power release during three sets of 3 repetitions at maximal effort on an isokinetic dynamometer compared to a placebo. Electromyography measurements (measurements of the electrical activity of muscles during contractions) also showed that glucose did not alter muscle fiber activation.
The results of this study were predictable, as adenosine triphosphate (ATP) and creatine phosphate are the primary energy sources for short bursts of intense activity.
(Journal Strength Conditioning Research, 30: 194 - 199, 2016)
High protein diets are effective for weight control as they suppress appetite, reduce insulin secretion and lower post-meal blood glucose levels.
Australian scientists led by Amy Hutchinson of the Royal Adelaide Hospital showed that consuming a drink containing 30 or 70 grams of whey protein had no effect on energy intake, blood glucose, digestive hormones, insulin or glucagon (both hormones important for appetite control).
Consuming protein in small amounts throughout the day may be an effective way to modify appetite in people who want to lose weight on a calorie-restricted diet.
(American Journal Clinical Nutrition, 102: 1574 - 1584, 2015)
Gluten is a mixture of proteins found in wheat, barley and rye. Gluten gives bread its elasticity and helps to give cereal products their firm texture. Gluten is an important source of protein worldwide and a significant protein supplement. Around one or two percent of the population suffer from celiac disease and are allergic to wheat. Symptoms of this allergy can include a range of sometimes serious gastrointestinal disorders.
Some dietary fanatics have extrapolated the gluten problems of people suffering from celiac disease to the entire population, which is ridiculous. In response, many manufacturers are producing gluten-free foods to appease this hysteria. Gluten-free foods have no positive effects on people who do not suffer from celiac disease.
Dana Lis and colleagues from the University of Tasmania in Australia have found that a gluten-free diet has no effect on performance, gastrointestinal symptoms, well-being or inflammatory markers in healthy athletes.
Gluten is an important nutritional component in people who do not suffer from celiac disease.
(Medicine & Science in Sports & Exercise, 47: 2563 - 2570, 2015)
Citrulline is an amino acid that promotes protein synthesis and fat breakdown.
A study conducted at the French Decartes University in Paris with overweight rats fed a high-fat diet found that supplementation with citrulline reduced blood sugar production in the liver and stimulated fat loss in the abdominal area. Citrulline increases the activity of brown adipose tissue, which increases calorie consumption and promotes fat burning.
Brown adipose tissue is a highly thermogenic tissue that releases energy as heat instead of storing it as fat. Citrulline increased levels of hormone-sensitive lipase by 150 percent, which also promoted the mobilization and utilization of fat.
(Molecular Nutrition Food Research, 58: 2320-2330, 2014)
