Imagine enjoying as many years in retirement as you spent working. Think of all you’d be able to see if you could travel well into your 120s. How about sticking around to celebrate the birth of your great-great-great grandchild?
Advertisement
For the approximately 1700 members of the Calorie Restriction (CR) Society (www.calorierestriction.org) — a non-profit group that promotes strict calorie (locally referred to as kilojoules; one calorie = 4.18kJ) control as a means to living longer — this post-centenarian life isn’t just a dream, it’s a goal.
Mary Robinson, a senior manager at a technology company, shares that goal. When she turned 47, Robinson decided it was time to make changes. “I was having lots of minor health problems and felt old,” she recalls.
“I made a resolution to lose weight and see if I felt better.” Robinson put herself on a calorie-restricted diet, using nutritional analysis software to track her every bite. “I went down 900 calories (3762kJ), lost 13kg in six months, and felt 100% better.”
As defined by the society’s members, calorie restriction means you consume a specific, limited number of calories while meeting all your nutritional needs. Depending on your height, weight, age and body type, that could translate to anywhere from 1000 to 2000 calories a day, give or take a couple of hundred.
“The average calorie intake for people on the CR diet is 1700 calories per day,” says Luigi Fontana, a professor at Washington University in the US, and a top researcher on calorie restriction.
The society encourages slow, steady weight loss, cutting no more than 100 calories a day until you’re losing about half a kilogram a week. The long-term goal is to take your weight down by 10 to 25% of your “set point” or what you weighed when you were neither overweight nor underweight.
Once your Body Mass Index (BMI, calculate yours) hits 20, the goal switches to weight maintenance. Society president Brian Delaney says these are realistic goals for reaching the level that provides the most benefits.
The science behind CR
Does the CR diet work? It does for rats and monkeys. In his numerous studies on rodents and other small mammals, Fontana has found that restricting calories while also providing sufficient nutrition can lead to a 50 percent increase in lifespan. However, there’s not much human research on restricting calories.
“It’s hard to find people willing to stay on a strict diet for the decades needed to prove whether or not they live longer than people who don’t follow the diet,” says David Katz, director of the Yale-Griffin Prevention Research Centre in the US.
But the results of human studies performed on middle-aged CR followers evaluating biomarkers — or conditions that lead to chronic disease — have been promising.
A 2006 study published in the Journal of Clinical Endocrinology and Metabolism found that people on CR diets had reduced levels of a thyroid hormone that increases free-radical production, which can lead to cancer and other chronic diseases.
And a report published in the Journal of American College of Cardiology (January 2006) found that the same group of people had above-average diastolic blood pressure, an indicator of future heart health.
The good, the bad and the hungry
In a country where two-thirds of adults are overweight, few health professionals can argue with a plan that encourages followers to reduce total calorie intake by eliminating highly processed foods and replacing them with more wholesome foods.
“For anyone who is overweight, reducing calories by eating more nutrient-dense foods will help reduce the risk of developing many chronic diseases like cancer, cardiovascular disease, osteoporosis, and arthritis,” says Jeffrey Blumberg, professor at the Freidman School of Nutrition Science and Policy at Tufts University in the US.
“This diet may or may not increase your life span, but it can certainly help increase your health span.”
But severe calorie restriction is a concern among many health professionals, and some mental health experts feel that counting every single calorie may not be so good for the psyche.
“It depends on the motivation for the diet, whether it’s strictly for health purposes or if it’s a distraction used to fill a void in your life,” says psychotherapist Glenn Berger.
“Like any obsessive behaviour, spending time thinking about each and every calorie consumed could be a way to avoid developing an authentic relationship, with yourself and with others.”
In short, what seems like a healthy, calorie-controlled diet to one might be an eating disorder to another. So just where does calorie restriction stop and anorectic behaviour begin?
Members of the CRS see clear differences, in both goals and attitudes. While anorectics focus on physical appearance, CR practitioners focus on health and longevity. Someone with anorexia sees food as a negative thing and eating as something to be done secretly.
CR practitioners generally enjoy eating and are happy to share their thoughts about food with others, they say. And while the primary goal of someone with anorexia is to be thin, the objective of someone who follows a CR diet is to live a long time.
Practitioners of CR routinely experience the gnawing hunger that comes with any low-calorie diet. “Calorie-restriction guides put a lot of emphasis on supporting people as they overcome hunger,” says Malena Perdomo, of the American Dietetic Association.
“But hunger is a natural, physiological response that we should listen to, not try to ignore or be talked out of.”
Even CR practitioners admit that handling hunger is tough. “One of the benefits of joining the group is to be in touch with people who share the challenges of what can sometimes be a difficult experience,” says society member Bob Cavanaugh.
A commitment to healthy eating
If calorie restriction in and of itself promoted longevity, we could all live on coffee and cigarettes. Or we could we eat half a hamburger, half an order of fries, and half an ice-cream cone, wash it down with half a can of soda, and call it a reduced-calorie meal. But that’s not how it works.
“The key is to replace nutritionally-poor foods with nutrient-dense foods like fresh fruits and vegetables, low-fat diary products, whole grains, and legumes,” says Fontana. This naturally promotes a decrease in calories and an increase in the nutrients essential for longevity.
Five years later, Mary Robinson has kept off her excess weight by continuing to monitor every meal. She insists it’s easier than it looks. “I get a lot of pleasure from eating good foods,” says Robinson, whose staples include steamed vegetables, high-fibre cereal, grilled salmon, nuts, and fresh berries.
“I visualise how the food makes my body feel, and that makes healthy eating feel more like a spa treatment than deprivation.” The biggest downside? Enjoying a meal when relatives and friends try to sabotage her efforts. “I try not to be inflexible, but I can tell you that I don’t share the joy when someone shows up with a batch of brownies.”
Despite the uncertain outcome of following a CR diet, Robinson plans to keep at it. “I still have a lots of things to accomplish in my life, and I hope this diet will help me stay mentally sharp and physically capable for as long as possible.”
Should we be joining the CRS
Shape asked registered dietician Maya Snijders-Naumann, a registered dietician in private practice and founder of Soundbites Nutrition, for her opinion on calorie-restriction.
Firstly, whether we are restricting calories for the sake of health and longevity, or for changing our body shape, the mechanism to do so would be restricted eating, i.e. dieting and dieting has its “side effects”, particularly if we’re talking about trying to get below our natural weight, as this organisation advocates.
For some, a BMI of 20 is perfectly normal, and they can maintain that easily by working with the natural regulatory system of the body. For an individual whose natural weight is higher, however (and just going by the bell-shaped curve, that’s the majority), it’s a different story.
The body will fight back, and it has many weapons in its arsenal — enough to significantly diminish the quality of life of the person involved (make them feel really miserable) in an attempt to get them to do what it takes to return to a normal weight.
The most well documented consequences of under-eating/dieting are:
1. Metabolic changes — decreased energy output, increased ability to store fat, increased production of saliva and digestive hormones and secretions in response to food cues and ravenous hunger.
2. Basically, the body becomes super-efficient at digestion and tries to trigger overeating in order to get the nutrients it needs for survival.
3. A heightened state of arousal — i.e. the dieter experiences stress for various reasons when restricting food intake, pushing their “baseline” stress levels higher than those of their non-dieting counterparts. Under normal circumstances, this does not cause any problems, but when stress is compounded by other factors (wet towel on the bed, traffic jam etc), dieters go “over the edge” much faster than others would and become hyper-emotional.
4. Loss of internal standards. Something that makes us feel secure, competent and sure of ourselves is our ability to successfully take care of ourselves by following our internal compass. Dieters “outsource” the regulation of eating to an external standard, such as calorie counting. By doing this, they enter an unnatural state in which they are alienated from their own bodies, and learn to distrust their intuition in the area of eating. This has a knock-on effect in other areas, which may explain why dieters become nervous and overly dependant on external guides for action in all areas of their lives.
To be frank, I’d rather die 10 years earlier than live longer in a state of chronic deprivation. And whether I would actually live 10 years longer if I ate less I think the known contributors to longevity — community, loving relationships, a sense of meaning, good food and movement, together make a far more positive impact.
(Julie Meyer and Toni Younghusband, Shape magazine, June 2007)
Imagine enjoying as many years in retirement as you spent working. Think of all you’d be able to see if you could travel well into your 120s. How about sticking around to celebrate the birth of your great-great-great grandchild?
Read more: 
Bookmark with:
What are social bookmarks?