The Health Benefits of a Calorie Restriction Diet
Studies have shown that eating a diet that is low in calories can lead to a longer and healthier life. This is known as the Calorie Restriction Optimal Nutrition (CRON) or Calorie Restriction diet (CR). This does not mean a starvation diet, since that would be the opposite of health.
The use of the word “diet” in this article does not mean a diet you start and then stop. This is their everyday daily diet, a lifestyle.
The health Benefits of a Calorie Restriction Diet
A study of Biosphere residents and participants of the Calorie Restriction Optimal Nutrition Society, who lived on restricted calories for an average of 6.5 years, found that they had significant decreases in their cardiovascular risk factors, lower diastolic blood pressure, lowered C-reactive protein and lower systemic inflammation (tumor necrosis factor-alpha) . All of this means a lower risk of heart disease, cancer and other diseases [2, 3]. In other words, they had younger values than their age would indicate and their hearts looked 15 years younger and had a more “elastic” heart. The participants in the studies did not have parents or grandparents who had prolonged lives.
Other studies found a longer and healthier life span when calories were reduced by 30% to 60% in lab animals. These results don’t seem to be the result of lower weight since there was no prolonged life results seen when lower weight was accomplished through exercise, only lowered calories . Some on the calorie restriction diet either don’t exercise or exercise minimally.
How Many Calories Do You Need
This is not just reduced calories; it is lower calories and maintaining proper nutrition. The participants in the Washington University of St. Louis study ate between 1400 and 2000 calories per day (average of 1671 calories) compared to 2445 calories for the average American diet. The study individuals had an average BMI (body mass index) of 19.7 compared to 27 for the average American .
We all need a certain amount of calories just to function, add any activity and your calorie needs go up. Calories are energy and you need energy to function, your brain, organs and muscles all need calories, nutrients and energy. You should first get your BMR (basal metabolic rate) number. This is the number of calories that your body uses up if you just stayed in bed all day. And then you multiply the BMR by a certain number depending on your daily level of activity to get the amount of calories you need to maintain your current weight. A very active and physical lifestyle uses many calories, so the calorie restriction diet might not be a healthy choice for those people .
You should not eat any less than 1200 calories for a woman and 1500-1800 calories for a man; any fewer calories and you can put your body into a starvation mode, which makes the body think it’s in a famine. That can cause your body to start storing fat. If you eat too few calories per day, your body will start taking from the muscles and organs.
What Should You Eat on a Calorie Restriction Diet
The goal is to eat between 1600 and 2000 calories per day. The most important part of the calorie restriction diet is an emphasis on nutrition. Calorie restriction does not mean eating only half of a Big Mac and drinking half of a soda pop. Every calorie has to be packed with nutrition or nutrient dense and not empty calories. Eating nutrient dense foods means no processed foods, fast food or junk foods since those foods have too many calories and too few nutrients.
We need to eat protein, carbohydrates and fats in order to be healthy. Eating any diet that eliminates any one of these three would be depriving your body of important nutrients. You do not have to eat meat or animal foods in order to get protein; you can get plenty of protein eating a vegetarian diet. Luigi Fontana, M.D., Ph.D., assistant professor of medicine at Washington University in St. Louis says that the calorie restriction diet resembles the traditional Mediterranean diet.
There is no general agreement among those who live by the calorie restriction diet as to the proportion of foods, but it seems that 40% carbohydrates, 30% protein and 30% fat is what most strive for, getting most of their protein from plant foods such as beans, legumes, lentils, quinoa and other plants sources. This restricts the amino acid methionine, which is found in animal foods and has been found to hinder prolonged life in animal studies. The Institute of Medicine recommends .8 grams of protein per kg of body weight. Many use nutrition tracking software to make sure they are getting all of the nutrients for a healthy life.
In the Washington University study, the 1671 calories contained more than 100% of the RDA for nutrients. Complex carbohydrates accounted for 49%, protein equaled 23% and 28% from fat with 6% of that from saturated fat. The diet was also low in sodium. 
Some practitioners of the calorie restriction diet do what is called intermittent fasting. Fast one day and eat the next, then fast the next and so forth. The difference with this method is that there is no calorie restriction on the day they eat, but always keeping nutrition important.
The choices are endless for lower calorie and high nutritional meals, lean meats, some fish, beans, vegetables, fruits and about any plant foods. You have to count calories, weigh your meals and become knowledgable about nutrition.
Calorie Restriction Diet Warnings
Calorie restriction diets are not anorexia, which is an obsessive fear of gaining weight and can lead to physical and mental illness. The calorie restriction diet should not be started by anyone still growing since it could stunt growth. A calorie restriction diet shouldn’t be done while pregnant, nursing or ill. Starting a highly restrictive calorie diet later in life could cause ill health. A calorie restriction diet started later in life should be less restrictive and started slowly so the body can adapt .
Reviewing studies over the past 40 years, Dr. Fontana has concluded that the calorie restriction diet may actually be harmful to lean people who have minimal amounts of body fat . Do not jump into this without doing plenty of research first.
© 2010 Sam Montana
References and helpful Articles:
 Washington University in St. Louis
 Roy B. Verdery, PhD, MD; Roy L. Walford, MD
 Fontana L, Meyer TE, Klein S, Holloszy JO. Long-term calorie restriction is highly effective in reducing the risk for atherosclerosis in humans Proc Natl Acad Sci USA 2004;101:6659-6663
 Journal of the American College of Cardiology J Am Coll Cardiol, 2006; 47:403-404, doi:10.1016/j.jacc.2005.10.030
 Scientific Psychic- Calorie Restriction Diet
 National Institute of Diabetes and Digestive and Kidney Diseases - National Institute of Health
 Roy Walford - "Beyond the 120 Year Diet: How to Double Your Vital Years"
A dietary intervention to increase life span
 Luigi Fontana, MD, PhD; Samuel Klein, MD, "Aging, Adiposity, and Calorie Restriction", JAMA. 2007;297:986-994
Dr. Oz interviews people living the Calorie Restriction Diet
Optimum Nutrition - What you need to eat
Nutrition calculator you can download