Nutrition
People lose 20 percent of their muscle mass between the ages of 40 and 60, and muscle loss continues thereafter. This results in reduced strength and power, as well as a reduced quality of life. This muscle loss also reduces the ability to regulate blood sugar, as muscles are responsible for about 30 percent of glucose utilization after eating. This reduces the risk of heart disease.
A literature review conducted by Scottish scientists concluded that high levels of omega-3 fatty acids in the muscles prevent muscle breakdown in old age by preventing inflammation and preventing insulin resistance.
Omega-3 fatty acids from fish promote metabolic muscle health.
(Marine Drugs, 13: 6977 - 7004, 2015)
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Bodybuilders and active people often use short periods of fasting to lose body fat quickly. Unfortunately, fasting shuts down biochemical pathways - particularly the mTOR pathway - that promote muscle growth. During fasting, cells - especially muscle cells - atrophy and use their cell contents for energy.
A Japanese study conducted at Juntendo University School of Medicine in Tokyo on fasting mice found that exercise activated the mTOR pathway, which is responsible for protein synthesis, and slowed down pathways associated with fasting that are linked to atrophy.
People who use short-term fasting for weight loss should exercise to minimize the loss of muscle mass.
(Biochemical and Biophysical Research Communications, 456: 519 - 526, 2015)
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Only about five percent of people who lose a significant amount of weight are able to maintain that weight loss for more than a year. Despite this depressing statistic, some people do lose weight and are able to maintain their new weight.
The National Weight Control Registry tracks the progress of people who have successfully lost at least 30 pounds of weight and have been able to maintain that weight loss for a year or more. One thing these people have in common is that they burn an extra 3000 kcal per week, which means they exercise for about an hour a day. Furthermore, successful dieters have only moderately restricted their calorie intake during the diet. You can further increase your chances of success if you maintain your muscle mass while losing weight.
Researchers at Maastricht University in Holland, led by Roel Vink, found that the people who lost the most lean body mass during their diet gained the most weight back the fastest.
You can maintain your muscle mass while dieting by exercising intensively and eating a high-protein diet.
(Obesity, 24: 321 - 327, 2016)
Growth hormones help to regulate fat metabolism. Many people use growth hormone injections because they trigger fat loss.
Can we manipulate the natural release of growth hormone by manipulating the composition of the diet? A study led by Hiroto Sasaki of Ritsumeikan University in Shiga, Japan, found that three-day diets that were high in fat and low in carbohydrates, or low in fat and high in carbohydrates, had similar effects on growth hormone levels in healthy men. At the end of each three-day diet, the men cycled for 30 minutes at 60 percent of maximum intensity on an ergometer. Post-exercise fat utilization was higher when the men consumed a high-fat, low-carbohydrate diet, but these changes were temporary.
Short-term dietary modifications have no effect on growth hormone levels in the blood.
(Growth Hormone & IGF Research, 25: 304 - 311, 2015)
Carbohydrates are the primary source of energy during exercise at an intensity of more than 65% of maximum effort. We have known for over 50 years that people have better endurance when they follow a carbohydrate-rich diet.
Scientists from McMaster University in Canada have found that performance release increases more after low-carbohydrate diets than when exercising on a high-carbohydrate diet. The scientists introduced the concept of HI-LO carbohydrate training. The test subjects completed two interval training sessions per day for 2 weeks. Each training session was preceded by a high and then a low carbohydrate intake (HI-LO). Another group followed a high carbohydrate intake (HI, HI) before each training session. The high and low carbohydrate program resulted in a higher power release at the end of the study.
The scientists only used moderately trained college students, so it is not clear whether the results are transferable to serious or elite athletes.
(International Journal Sport Nutrition Exercise Metabolism, 25: 463 - 470, 2015)
