Caloric restriction, defined as reducing calorie intake by at least 30 percent, has gained a cult following since it was first studied in the 1930s. Scores of people swear that by dialing consumption way down, and eating far less, you can gain vitality and longevity. And while studies cited by the National Institutes of Health report that caloric restriction (often referred to as “CR”) did have some positive effects on health in rhesus monkeys, the NIH announced in 2012 that it has not been shown to boost overall longevity. (These findings conflicted with those published in 2009, which found that caloric restriction did, in fact, extend life in monkeys.)
The final word on these studies has yet to be published. But I don’t believe we need to wait for it. If you want to live a longer, better life, portion control plays a role, sure— but the reason I’m not one for the CR diet is because I believe you should be far more focused on what’s ON your plate, rather than what isn’t.
The danger inherent to the idea of caloric restriction is the belief that simply consuming less food is enough to fend off chronic disease and give you optimal health— without much concern for the food itself. If this were true, we’d all be able to eat cheeseburgers and french fries in smaller portions every day and call ourselves healthier. If you put emphasis on what you’re not eating rather than what you are, you’re missing the mark.
A great example of what I mean is the popular diet program Weight Watchers and similar plans such as Nutrisystem, which completely flop in terms of nutritional benefits. They certainly restrict your daily caloric intake and you may lose weight, but with Weight Watchers, you could still end up eating a slice of pizza at each meal and stay within your allotted “points” for the day. You’re still consuming a high-carbohydrate, low-nutrient diet— essentially an inflammatory diet— and this puts you at risk of all the top killers, including cancer, heart disease, and even Alzheimer’s disease and dementia later in life. Eating a limited number of calories does not necessarily equal a health-promoting, life-extending diet.
Some of the caloric restriction research findings also point to the importance of food quality and, I believe, give us a clue to the longevity puzzle. In the two studies I mentioned above, launched in the ‘80s and coming to a close now, the calorie-restricted monkeys were fed different kinds of food. One group, studied at The University of Wisconsin, was fed a diet high in sucrose, or sugar, that lacked trace dietary chemicals and minerals. Not surprisingly, when this unhealthy diet was given in lower quantities, the monkeys experienced better health and lived longer lives— and control group monkeys that were given unlimited quantities of this food died earlier. By contrast, in the other study, calorie-restricted monkeys as well as the control group monkeys were fed a natural-ingredient diet. This resulted in about the same health outcomes between them.
So while limiting nutritionally poor food will help your health, you should focus on replacing lousy foods altogether. What I recommend to you is the same thing I tell my patients every day: Your best shot at keeping chronic diseases at bay and extending your lifespan is replacing high-sugar, processed foods with a wholesome, nutrient-dense diet of fruits, vegetables, lean proteins, legumes, some grains, nuts and seeds.
Is half of your plate filled with plant-based foods at each meal? Do you have a lean protein and a healthy fat represented on your plate? Are you consuming clean food that is as close as possible to its most natural state? If not, quit counting calories and focus on making these changes.