So we all know that a reduction in calories equals weight loss. While this is important for those of us who want to lose weight, there are other benefits to calorie restriction. For example, a reduction in caloric intake has been believed to delay the rate of aging by reducing oxidative stress to proteins, lipids, and DNA. It has also been shown to decrease the amount of free radicals in the body. Free radicals are very unstable molecules that “attack” other molecules to “steal” there electron. This is important to note because a large amount of these molecules can damage other cells, including muscle. So what else can calorie restriction do and what does this recent research tell us?
The study methods
The purpose of this study was to determine if calorie restriction is linked to muscle mitochondrial production. The mitochondria of the muscle cells are the organelles that generate most of the energy used by the cell. So does calorie control provide more energy for our muscles? 36 young, overweight individuals were recruited for this study. Each was assigned to a group. They either retained a weight maintenance diet, reduced their calories 25% from baseline energy requirements, or reduced their calories 25% from baseline and underwent structured exercise (walking, running, cycling) for at least 5 days per week.
The methods explained
For each individual, body composition, fasting insulin, and plasma glucose were measured before and after the 6-month intervention. In order to measure how much mitochondria was present in a muscle cell, a muscle biopsy was performed. After analysis of markers obtained in the biopsy, the number of mitochondria was determined.
Based on Table 1 below, it is clear that metabolic characteristics such as weight, body fat percentage, and fat mass decreased significantly with a reduction in calories, particularly when combined with exercise.
The results also proved that the concentration of mitochondria increased significantly in both the caloric restriction group and the caloric restriction with exercise group.
The study outlined confirms what we know about calorie restriction: it leads to weight loss. While this is important to note, it is also clear that calorie restriction leads to increased mitochondria presence in muscle cells. So what does that mean? More mitochondria equals more energy within the muscle; more energy within the muscle equals more gains.