Calorie restriction (CR) is a dietary approach that involves reducing energy intake without causing malnutrition. It has gained attention for its potential to improve health and manage aging-related diseases.
While research in humans is still in its early stages, studies suggest that CR may offer significant benefits in addressing conditions such as cancer, cardiovascular disease, dementia, and diabetes.
Calorie Restriction and Disease Management
Research has shown that decreasing caloric intake by 20-30% while meeting nutrient requirements can help remedy diseases of aging. In humans, this reduction in calories has resulted in an average weight loss of 7.9 kilograms (17 pounds). However, due to the long lifespan of humans, definitive evidence that CR can prevent age-related diseases remains under preliminary research.
Calorie restriction has been associated with various health benefits, including improved lipid profiles and decreased resting heart rates. These changes suggest that CR might contribute to better cardiovascular health. Additionally, CR has been linked to lower insulin resistance, reduced levels of LDL cholesterol, and less oxidative damage to DNA. These factors are crucial in reducing the risk of chronic diseases and promoting overall health.
Potential Risks and Considerations
While calorie restriction offers potential health benefits, it is essential to approach this dietary regimen with caution. Moderate amounts of calorie restriction may have harmful effects on certain population groups, such as lean individuals with low body fat. Therefore, it is crucial to ensure that nutrient requirements are met to avoid malnutrition.
The Minnesota Starvation Experiment, conducted during World War II, highlighted the negative effects of extreme calorie restriction. This study involved lean men who restricted their calorie intake by 45% for six months. While some metabolic adaptations were observed, such as decreased body fat and improved lipid profiles, the experiment also resulted in negative effects like anemia, muscle wasting, and irritability.
Ongoing Research and Future Directions
As of 2021, intermittent fasting and calorie restriction remain under preliminary research to assess their possible effects on disease burden and increased lifespan during aging. The relative risks associated with long-term fasting or calorie restriction are still undetermined. Intermittent fasting, which involves periods of no food intake except for clear fluids, could be combined with overall calorie restriction and variants of the Mediterranean diet to contribute to long-term cardiovascular health and longevity.
The ongoing CALERIE study is a significant research effort aimed at understanding the long-term effects of calorie restriction in healthy humans. This study hopes to provide more insights into the potential benefits and risks of CR, ultimately contributing to a better understanding of its role in managing aging-related diseases.
