Saturday, January 16, 2010

Calorie restriction: For health, not for weight

Calorie restriction, besides the weight-loss effects we are all seeking, may also have some serious health benefits. A recent New York Times article describes a current study called Calerie, which is being conducted to discover whether, besides lowering risks for weight-related diseases like heart disease and diabetes, calorie restriction might have an effect on the aging process:
Essentially, the study asks whether calorie restriction allows people to grow older in better health — with less disease, fewer drugs and shorter hospital stays — through a method that neither medicine nor scientific technology have yet come close to approximating. Meanwhile, the experiment aims to shed some light on the more complex and still-unsettled question of whether calorie restriction affects primary aging, and thus longevity, in humans. Going back more than a half century to an experiment at Cornell University in the mid-1930s, calorie restriction has been shown again and again to extend the lives of mice, rats and other animals. An ongoing experiment at the University of Wisconsin on rhesus monkeys, which began in 1989, portends similar results: compared with normal-weight primates on a regular calorie regimen, the monkeys on restricted diets are healthier and more vigorous and seem destined (at least at the moment) for a longer life.
It is fairly simple to study the effects of calorie restriction on animals confined to a lab. They eat whatever they are fed because they have no choice. It's a little more difficult with human volunteers, even committed ones. A wartime study with conscientious objectors that forced subjects to reduce their calories by 40% resulted in serious psychological consequences. The current study is a more moderate calorie restriction. The researchers recruited volunteers with a BMI between 22 and 28 who were healthy and motivated. The researchers then tested the volunteers' metabolisms to see how many calories they burned daily, then cut that number by 25% to determine their calorie-restricted intakes. The subjects were provided with meals for the first 28 days to help them learn their new regime, and then they were responsible for preparing -- and logging -- their own meals and snacks.

What is interesting about this to me as a weight-loss blogger is how much empathy there is for subjects facing the challenges of eating less (moving more is not recommended in this experiment). There is no condescension or judgment here. Maybe this is because volunteers are normal-weight to slightly overweight and are not primarily interested in weight loss -- though that is an expected side effect of the study and may be responsible for many of the anti-aging effects of calorie restriction. The article described a 175-pound man whose weight was expected to drop to about 147 pounds. The researchers, even though they believe in the benefits of calorie restriction, were not expecting many of the subjects to stick with it after the study was over. Accurate calorie counting and meal planning are difficult for everyone, one said.
“I don’t think humans are designed to pay attention to how much they eat,” he said, adding that for most people this natural tendency would chafe against the organizational requirements of calorie restriction, thus limiting its appeal.
A 25% calorie reduction is, incidentally, what I'm currently struggling with myself. I am aiming for around 1700 calories a day, but have been averaging more like 2,200 - 2,300. As weird as it is possible to take diet tips from a research study, it is interesting to see what the researchers are doing to help support the subjects in their efforts. First, of course, there are the weighed and measured meals provided for the first month of the study. The researchers also steered subjects toward high-volume, low-calorie-density foods.

If you don’t change your diet to a high-satiety diet, you will be hungry, and you will fail,” she told me. A high-satiety diet, she said, was bound to be a healthful diet with a lot of vegetables, fruits and insoluble fiber — the kind found in some breakfast cereals, like Fiber One — that her research indicates has a unique effect in helping calorie-restriction subjects feel fuller, probably because they activate certain receptors in the lower intestine.
Subjects were also encouraged to plan ahead by banking calories for special events and be selective about high-calorie foods. Most give up or strictly limit alcohol. After a few weeks, hunger settled down and they learned to eat foods like apples that filled them up for less calories. What subjects complained most about was the hassle of planning, looking up calorie counts, and recording every bite. The benefits, especially to cardiovascular health, are pretty amazing:
His subjects have cholesterol around 160, blood pressure around 100 over 60, high HDL, low triglycerides and very low levels of inflammation. . . “I don’t know why anyone would take drugs when they could do something like this,” Roberts said, referring to Calerie.
The biggest thing I think I took away from this article was a sense of how much easier dieting would be if I looked at it from a more matter-of-fact stance. Yes, restricting calories is challenging. There are ways to make it easier but they involve planning, thought, and time for cooking and shopping. There are also some serious benefits. Best of all, the hunger might actually subside if I could give myself enough time at the lower calorie level to adjust to it instead of getting upset because I'm hungry and eating more, then feeling bad about that choice. What would dieting be like if it involved less judgment and self-flagellation and more matter-of-fact discipline?

Food for thought, anyway.


  1. The hunger does go away. What doesn't go away (for me) is the feeling of being cheated during holidays or social events and so forth. After a while, resentment can sometimes take the place the hunger. It's not reasonable at all, really. But calorie counting becomes tedious, stressful ... and that's where it gets hairy.

    I say that as a calorie counter with some success under my belt. It works. And it also sometimes drives me crazy.

  2. Interesting study and insights. Counting calories is hard and gets boring because it's so easy to get caught up in looking for the lowest numbers - which can end up leaving us feeling deprived and angry. Well, okay, maybe just me.

    There's room in a healthy balanced food plan for low calories but also reasonable amounts of carbs, fats & proteins which can make us feel more full and less deprived. And yeah, that definitely takes time to figure out. As people with intentional weight loss needs, we can never stop paying attention.


"Count your calories, work out when you can, and try to be good to yourself. All the rest is bulls**t." -- Jillian Michaels at BlogHer '07