Calorie restriction is a simple and healthy way of shredding some weight. It means reducing average daily caloric intake below what is typical or habitual, without malnutrition or deprivation of essential nutrients.

“Reduce” can be defined relative to the subject's previous intake before intentionally restricting calories or relative to an average person of a similar body type. Commonly consumed food components containing calories are carbohydrates, proteins and fat.

Calorie restriction is said to be the ‘gold standard’ of life-extending interventions that do not involve drugs or genetic manipulations.

The diet has been shown to extend the lifespan of various organisms like yeast and worms, spiders, and flies. It is also effective in mammals, with CR showing life-extending effects in mice, rats, dogs, cows, and rhesus monkeys.

Does it actually work?

Evidence that calorie restriction retards aging and extends median and maximal life span was first presented in the 1930s. Dehydroepiandrosterone sulphate plays an important role in this process and is found in higher concentrations in people who practice calorie restriction. The importance of dehydroepiandrosterone sulphate is not yet known, but it is suspected to be a marker of longevity in humans. A major goal of research into aging has been the discovery of ways to reduce morbidity and delay mortality in the elderly.

What are the benefits of calorie restriction?

  • Gradual weight loss.
  • Muscle preservation.
  • Longer life.
  • Prevents heart disease, diabetes, and stroke.
  • Prevents cholesterol and blood pressure.

What can be the side effects?

  • Risks of malnutrition.
  • Fatigue and deficiency in nutrients.
  • Triggering binge eating.
  • It may weaken your bones.
  • It may reduce immunity.

To compensate for the deficiency in nutrients it is advisable to take vitamins and various nutrient supplements to avoid any problems with your calorie-restricted diet.

Calorie needs vary from person to person because they depend on factors such as age, sex, height, current weight and physical activity level.

Determining the number of calories that's right for you will reduce your likelihood of developing the negative health consequences outlined above.

  • Determine your BMR: to estimate the minimum number of calories your body requires.
  • Estimate your daily requirement: to estimate the number of calories you need to maintain your current body weight.
  • Determine your calorie needs for weight loss: If weight loss is your goal, aim for a daily calorie intake falling between the amount required to sustain your BMR and the amount needed to maintain your current body weight.

Burn more calories than you take or eat fewer calories than you burn.

What kind of foods will help in this process?

Fill up on foods that are high in water, fibre or protein. Cucumbers, for example, are over 95 percent water and have just 8 calories per cup, so enjoy them anytime without having to worry about your weight. Protein-rich foods, such as turkey breast, tuna and eggs, increase satiety and may improve body composition, while fibre keeps you full longer.

While you may lose weight by limiting your intake to 1,000 calories a day, this may be too few calories and place you at risk of nutritional deficiencies. Men shouldn't eat fewer than 1,500 calories a day and women no less than 1,200 calories.

(Article by Dr. Thiago Freire and Yuvashri Ravi).