Nutrition
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)
Bulletproof Coffee is a drink that contains coffee, unsalted butter from grass-fed cattle (rich in omega-3 fatty acids) and medium-chain triglycerides (MCTs).
Medium-chain triglycerides are fats that, like all fats, provide a large amount of energy in a small volume, but are still quickly absorbed and metabolized in a similar way to carbohydrates. Medium-chain triglycerides may reduce body fat, improve the metabolism of carbohydrates and proteins, increase the absorption of essential elements such as calcium and potassium, and lower the risk of heart disease by reducing blood cholesterol and triglyceride levels.
There are claims that the Bulletproof line of beverages reduces hunger, improves mental focus and accelerates weight loss. These claims are questionable. The brain mainly uses carbohydrates as an energy source, so the high fat content of the drink will not support the brain's energy supply. Studies conducted on animals show that high-fat diets reduce mental function and promote memory loss. People use Bulletproof Coffee as a meal replacement. One cup provides more than 300 kcal, which would promote fat gain if people were eating a normal diet at the same time. Furthermore, MCTs only caused a small amount of weight loss. Fads come and go, so it will be interesting to see if Bulletproof Coffee will still be around in a year or two.
(Lipids in Health and Disease, 13: 194, 2014; The New York Times, December 14, 2014)
