Caloric restriction ‘immortality’ is more complex than just decreasing your food intake
The caloric restriction (CR) diet plan has been around for decades, but recent studies show animals ranging from monkeys to fruit flies may be living longer because of this method.
But can people really increase their life expectancy just by decreasing the amount of food they eat? When practicing caloric restriction people cut out close to all processed foods and consume a diet primarily consisting of vegetables, fruit, healthy fats and lean proteins, including beans and lentils. As for liquids, they drink a lot of water, tea and black coffee.
A sample breakfast for a six-foot, 180-pound, 25-year-old man who does a moderate amount of activity is two slices of whole wheat toast with two tablespoons of peanut butter, a cup of skim milk, one orange, and tea or coffee with two tablespoons of milk and one teaspoon of sugar.
A sample lunch for a 25-year-old woman who stands at 5-7 and weighs 150 pounds is two cups of mixed greens with two tablespoons of low-fat dressing, three ounces of grilled salmon, half of a whole wheat pita, and one cup of non-fat yogurt.
Though such meal plans may sound simple enough to follow, some dieticians are skeptical about how realistic caloric restriction is for most people, saying it’s much harder to maintain than people think. Some dieticians also say people may not approach CR with the right intentions for their own health, and can even use the notion of practicing it to mask an eating disorder.
Patricia Chuey, a registered dietician and nutrition author, says that when considering caloric restriction as a dietary option, people need to consider the quality versus quantity aspect of their new lifestyle.
“Most people aren’t just after, ‘I want to live to be 100,’” Chuey explains. “I think if you ask people if they would rather have 90 good quality healthy years or would they rather live to 100 but the last 20 years of their life are awful, I would say most people are after quality.”
This definition of “quality of life” is different for everyone. For some, it may include enjoying the social aspects that usually come with food consumption. Andrea Hardy, a registered dietician based in Calgary, believes social limitations can be an issue when practicing caloric restriction.
“You’re limited in what you’re going to be allowing yourself to attend, like family gatherings and meals,” Hardy says. “So it’s just kind of weighing what sort of life you’re willing to live and what brings you the most joy.”
In terms of CR being a realistic option for people to achieve longevity, Hardy mentions that studies have identified intermittent fasting as another, potentially easier, eating plan option.
“With CR, generally you’re taking in about 60 to 80 per cent of the calories that you need for a day, whereas the intermittent fasting would be a feast day and a fast day,” she explains. “A lot of studies have chosen to do it this way in humans because they’re hypothesizing that we would find it easier to not eat for an entire day and then eat whatever we wanted for an entire day versus counting calories every single day.”
Since the 1930s, multiple long-term studies have found that lab rats and mice live up to 40 per cent longer when eating a diet that is reduced by 30 per cent. However, other studies have concluded that the age the mice and rats start caloric restriction can also have an impact on the plan’s efficacy.
Caloric restriction requires a high level of commitment and will power. This may explain the reason why all three registered dieticians who spoke with The Calgary Journal do not currently have any clients practicing CR under their guidance. But that’s not to say people haven’t asked them about it.
Jessica Begg, a registered dietician, says she has had people who match the criteria for disordered eating come to her with the latest study in hand supporting caloric restriction.
“They are trying to support their stance,” she says. “They say that these studies show if you restrict you will live longer, but there already is a whole host of things going wrong with them and they clinically have an eating disorder, so this is an argument they are using.”
But for those exploring caloric restriction diets for the right reasons and health benefits, Begg, although she doesn’t personally recommend CR, strongly advises seeking medical supervision or nutritional guidance to ensure one you are still consuming the right amount of nutrients.
“You are going to want to make sure you are getting as much nutrition out of [caloric restriction], so as much micronutrients and macronutrients in as little as you are going to eat. I think that would be the biggest issue,” Begg says.
If someone improperly practices CR long-term, they could run the risk of encountering several health problems along the way, says Hardy.
“With these people who are CR for the rest of their lives, they’re likely to be underweight, they’re likely to probably have a lower bone density and less muscle mass,” she says. “So are those extra five to 10 years they get, are they in health, or are they in illness because they’re malnourished?”
Whether you think you have what it takes to try caloric restriction, the key to remember is balance – honouring your body and doing it for sound reasons that match your lifestyle.
“There are people out there who can do this and do it successfully, and do it for what they believe to be the right reasons,” says Hardy. “They’re doing it for longevity or they’re doing it for their diabetes.”
“If you’re doing it for weight loss, I wouldn’t recommend it.”
Chuey believes the issue in choosing to adopt a CR plan or not “has to be interpreted individually. And individually is not just based on genetics, but it’s based on your core philosophy, who you are and how you want to live your life.”
The editor responsible for this article is Michaela Ritchie, firstname.lastname@example.org