According to a new study, which is the first to associate calorie restriction with delaying the onset of aging, cutting down on calories and restricting portions, really does work. The study is the first to show that long-term calorie restriction with good nutrition has cardiac-specific effects that influence the aging process.
It seems our hearts tend to stiffen and pump less effectively as we age, but the ultrasound examinations showed that the hearts of the people on caloric restriction appeared more elastic than those of the control subjects.
Luigi Fontana, M.D., Ph.D., from the Washington University School of Medicine in St. Louis, Missouri and the Italian National Institute of Health in Rome, says that eating less on a high-quality diet, will improve the health, delay aging, and increase a persons chance of living a long, healthy and happy life.
A number of previous studies have shown that animals can live longer when they eat fewer calories, but a human study has been difficult as a calorie restricted model requires a strict regime in order to ensure that the total number of calories is low and a balance of nutrients are consumed.
First-time author Timothy E. Meyer, Ph.D., designed the study and rather than attempting to randomize volunteers to different diets and then hope that they would stick to them for years, he asked the research team to compare 25 people who had been following caloric restriction for an average of six years, consuming about 1,400 to 2,000 calories per day, with 25 similar control subjects who were eating typical Western diets of about 2,000 to 3,000 calories per day.
The 24 women, who ranged in age from 19 to 35, adhered to four menu plans for two days apiece.
One plan had them eating standard portions of common foods like muffins, pizza, pasta and salad.
Another gave them lower-calorie versions of these same meals, reduced-fat snack food, for example, or dinners containing a larger proportion of vegetables.
A third eating plan gave the women full-calorie fare but smaller servings, while the fourth included both portion control and lower-calorie foods.
The researchers found that all three of the diet-conscious tactics cut the number of calories the women ate each day, but the combination of portion control and calorie-watching was most effective, lowering their calorie intake by 812 calories a day.
Many experts believe the obesity epidemic being seen in the U.S. and other developed countries is a direct result of the availability of cheap, often large portions of calorie-dense foods.
Lead study author Dr. Barbara J. Rolls a professor of nutritional sciences at Pennsylvania State University, says the results are exciting as the calorie drop was achieved without major changes to the diet, and without leaving the women feeling hungry at the end of the day.
They were also still able to enjoy such lower-fat versions of treats as brownies, potato chips and cheese and crackers.
Past research has shown that portion size can play a vital role in a person's calorie intake; the more food on the plate, the more food goes into the stomach.
In fact, cutting calorie density without cutting portions was more effective in this study than simple portion control.
Dr. Fontana, emphasizes that caloric restriction does not mean simply eating less and will only work in this way when used with eating good food.
He says calorie restriction when coupled with malnutrition accelerates aging and causes severe diseases, therefore, eating half a hamburger, half a bag of French fries and half a can of soft drink is not healthy caloric restriction and could be harmful.
Dr. Fontana compares the diet to the traditional Mediterranean fare, which is based on a wide variety of vegetables, olive oil, beans, whole grains, fish and fruit.
The diet avoids refined and processed foods, soft drinks, desserts, free sugars, white bread and white pasta.
While many people could adopt some of these diet practices, Dr. Fontana cautions that anyone attempting to follow a strict caloric-restriction diet should have expert guidance, because of the risk of malnourishment if the diet does not include the right amounts of key nutrients.