Researchers evaluate health benefits of calorie restriction

(Republished with permission from the St. Louis Post-Dispatch. This article originally ran in the Health & Fitness section on Monday, February 18, 2008.)

By Harry Jackson Jr. St. Louis Post-Dispatch

Washington University scientists want to find out if eating a lot less can improve your health to a nearly perfect condition.

That’s why they’re conducting human studies of a movement called “calorie restriction.”

It’s supposed to work this way: If you reduce your calorie intake by 25 percent to 30 percent, your physical fitness will improve to a nearly perfect level of health.

For example, a calculator used by the Mayo Clinic says an active man of 6 feet, 200 pounds, needs about 2,900 calories a day to maintain his weight. For a 25 percent reduction in calories, he’d go to 2,175 per day.

An active woman, 5-5, 140 pounds, needs 2,050 calories a day to maintain her weight. She’d drop to about 1,550 calories.

The first phase of CALERIE — Comprehensive Assessment of the Long Term Effects of Reducing Intake of Energy — began several years ago when doctors examined a small number of people from a group called the Calorie Restriction Society. The group has about 3,000 members.

Early tests showed the practitioners, who call themselves “CRONies,” (Calorie Restriction, Optimal Nutrition), had virtually no risks of cardiovascular disease or cancer even though their medical records said they were less healthy when they started the program.

What also intrigued researchers were claims that practitioners would live 20 to 30 percent longer and in better health.

Dr. John Holloszy, professor of medicine in the Division of Geriatrics and Nutritional Sciences at Washington University School of Medicine and the lead researcher on the project, says researchers can’t wait half a century to see if the longevity claims are true.

However, he wrote after the preliminary round of studies, “It’s becoming clear from studies with the CRONies — and from this brief, prospective study — that calorie restriction does change some of the markers we associate with aging.”

The federal National Institutes of Health agreed and is paying for a bigger study of several hundred people in three research centers — Boston, Baton Rouge, La., and St. Louis. These will be people new to calorie restriction.


Proponents of calorie restriction, which they call “CR,” boast of disappearing triglycerides, healthy cholesterol levels, the elimination of low-level inflammation through the body caused by oxidation damage, lowered and more stable blood sugar, nonexistent cardiovascular disease and even instances of being cured of early stage diabetes.

Holloszy says he’s not put off by claims that the practice could stretch useful and healthy life spans up to 120 years.

“With calorie restriction, it seems like the metabolism goes into slow motion,” Holloszy says, adding that the slower metabolism means slower aging.

“We’ll look at the (physiological changes) in the reduction of the processes that we know cause aging,” Holloszy says.

He added that early research shows some health benefits can come from reducing calories by 10 or 15 percent. “We think the effects may hold true (in proportion). We just don’t know yet.”


A seven-year practitioner of calorie restriction is Joseph Cordell, a St. Louis divorce attorney who specializes in men’s rights.

He adopted calorie restriction years ago. He was in good condition but wanted more. He read a book, “Beyond the 120 Year Diet” by Dr. Roy Walford, who’s considered the founder of the movement. Walford believed the rodent tests would translate easily to humans even before human studies were performed.

Today, Cordell has a breakfast of berries and apple peels. Through the day he’ll eat mainly vegetables, fruit and for dinner vegetables with a small amount of lean meat, such as salmon, chicken or even lean red meat.

“That’s the thing about calorie restriction,” Cordell says. “What I eat probably weighs more than what you’re eating, but it’s much more dense in nutrients and a lot fewer calories.”


The attraction to CR by researchers was sparked by more than 60 years of uncommonly consistent tests on laboratory mice and rats, Holloszy says. When laboratory animals were placed on calorie restricted diets, “their life spans increased 20 to 40 percent.”

Washington University performed the tests more than 10 years ago and came up with the same results, Holloszy said.

Bob Cavanaugh, a spokesman for the Calorie Restriction Society, says the group was founded on Walford’s principles. Thousands use the group’s website,


Both Cavanaugh and Cordell emphasized that calorie restriction is a way of life, not a diet; it’s not simply eating 25 percent fewer calories at each meal.

And it’s not easy, which is why CR practitioners created a supportive community. St. Louis doesn’t have a local group, although people here practice CR.

This is a simplified description:

— Examine your diet closely, detect the high-calorie, low nutrient foods, then eliminate them. They suggest weening, not simply turning them off cold turkey.

This will involve logging what you eat, maybe even seeking help from dietitians or other CR practitioners.

— As you eliminate empty calories, replace them with nutrient-dense foods, primarily vegetables and fruits. Cordell says he eats apple peels rather than the whole apple because that’s the source of the most nutrients. He also avoids high-sugar fruit such as pineapples.

— Once your whole diet is nutrient-dense foods, you can calculate the calories you’re eating and begin cutting back until you’ve eliminated 25-30 percent.

Cavanaugh says the CR Society offers a calorie and nutrition calculator to anyone who pays the $35 signup fee. Another, called “Cron-o-meter,” is free online.

Holloszy, however, recommended against doing this on your own because off the downsides. And even the CR Society lists risks, most of which come during the transition process.

For example, practitioners find that they lose both fat, muscle and bone mass. That’s why people who can’t afford loss of bone mass or muscle need to be cautious or reject CR alone or work closely with their personal physician.

As for others, “The body is marvelous at regulating itself,” Cordell says. “Your body maintains the amount of bone mass and muscle you need for good health. If you’re not carrying around so much weight, you don’t need the bone mass or muscle mass.”

He says he dropped to about 130 pounds from 170, living on about 1,500 calories a day.

Holloszy wasn’t ready to dismiss the loss of bone mass and muscle. He suggested daily exercise for people trying CR.


For maximum safety, Holloszy suggests joining the Washington University study. Researchers still need about 60 people.

Those accepted will be monitored by physicians, dietitians and physiologists who’ll meet with them weekly and help set up their diets.

The first month will be a tightly scrutinized eating plan to get you started. After “boot camp,” participants will be be given a stack of eating plans and recipes from various diets such as the Mediterranean Diet and diets based on low fat, low glycemic index or vegetarian.

For two years, they’ll have weekly contacts with the researchers and frequent blood tests.

“It’s quite a commitment,” Holloszy says.


Copyright 2008 St. Louis Post-Dispatch, Inc.