Dieting and Health

Obesity flourishes in Calabar, Nigeria, where the rich often rent “fattening rooms” to put on a few pounds. Many health deficits are associated with obesity, as shown by modern research, though. Diets combat obesity and promote good health and long life. In particular, a calorie restricted diet hopes to extend life by 30% and prevents illnesses. However, research proves that calorie restricted diets do not actually lengthen life or even remotely prevents early death any more than a healthy, well-balanced diet.

Rhesus monkeys of same age. Monkey on left was on
calorie restricted diet. Image by Jeff Miller

Some studies claim that calorie restricted diets promote long life. The WNPRC (Wisconsin National Primate Research Center) tested caloric restriction on the lifespan of Rhesus monkeys in 1989. The control monkeys received an unlimited amount of food and were allowed to eat whatever they wanted. In some ways, this simulates modern eating habits. We often go to the pantry, pull out the secret candy stash, or drive to McDonalds and eat until we feel sick. At college, we often stuff ourselves in the dining hall because we have limited meals, or stack up on pop tarts and ramen to get us through sleepless nights spent studying. The experimental monkeys were given a calorie restricted diet that consisted of unhealthy foods. In comparison, they ate a lot less unhealthy food than the control group, so they had favorable results. This part of the experiment was unrealistic, however. When people diet, they do not just cut back on percentage of what they eat. They strategically cut back on foods that they know are unhealthy and not necessary. Rather than a calorie restricted diet consisting of healthy foods, this study gave the monkeys a restricted diet consisting of unhealthy foods. A better designed study would have had the experimental monkeys eat a healthy calorie restricted diet (Bourzac, Live Long and Prosper).

The NIA(National Institute on Aging) also conducted a study on monkeys to test the effects of a calorie restricted diet. In this study, they had an experimental group that ate a calorie restricted, well balanced diet. The control group ate a well balanced, higher calorie diet. The results between these two groups were not significant. This study provided evidence that a well balanced diet is healthy, even if it isn’t restricted in calories. As long as you burn off the calories from the foods you eat, you can stay fit and healthy. Eating healthy foods makes it easier for your body to process while digesting and can improve internal health. The type of calorie restricted diet referred to in this study shouldn’t be confused with an overall calorie restricted diet. The study restricted calories by 30% from the suggested calorie intake. People often diet and restrict their calorie intake, but not below the suggested amount by the FDA. The dieting referred to in these studies is restricted below the suggested calorie consumption. 

Caloric restriction not only doesn’t provide any additional longevity over healthy dieting, but it also has some negative side effects. Rafael de Cobo from the NIA claimed that caloric restriction can have negative effects on the immune system. He remarked that some studies show slower wound healing and an increased risk for infectious disease. Your body uses a lot of the calories consumed to do things like move your muscles so you can perform daily tasks and function throughout the day. It can then be left kind of exhausted and perform internal actions much less effectively. The body may not have enough energy to properly heal up wounds or fight off diseases and illnesses. With decreased effectiveness in these essential bodily functions, additional longevity can’t be expected. 

These studies show that calorie restricted diets (significantly restricting calorie intake 30% below the suggested amount) only works when it is used to lower the intake of unhealthy food. A person with a healthy, well balanced, not absurdly high calorie diet would not benefit from cutting back their calorie intake to 30% below the suggested intake. However, a person who consumes lots of unhealthy foods would benefit from cutting back the consumption of these unhealthy calories. 

While these studies cleared up some important questions on dieting, they may have left you wondering about what physique type is healthiest. I know that a healthy diet doesn’t automatically imply a perfect, slim physique however, which can be important to people. But a slim, “socially perfect” physique may not be the healthiest afterall. A study published in January of 2013 investigated what physique (BMI) seemed to have the highest correlation with long life. The study found that obese people (a BMI of higher than 30) had a higher chance of all-cause mortality. However, the study found that slightly overweight people (with a BMI of 25-30) had significantly lower all-cause mortality. So healthy dieting is important, but super skinny doesn’t necessarily imply health (This skinny physique I refer to is considered the “healthy range” and is 20-25 for BMI). A little fat here and there can be a very good thing. It can even help you live longer!

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There are a few important things to note when discussing BMI as it relates to physique. BMI aims to provide an accurate measurement of the amount of fat somebody has on their body. It attempts to take the height and weight of an individual and provide a numerical representation of their body shape. However, it does not always accurately reflect the physique of the individual. A dense, muscular individual may have a high BMI when they in fact have very little fat on their body. 

Why does any of this matter for you health enthusiasts? Health should matter to everybody. You only have one body, and it’s your responsibility to take care of it. It can be difficult to know how to take care of it though. It can also be difficult to know how current actions can affect the future. Well balanced diets provide energy. When it comes to calorie consumption, there is no benefit over restricting intake to lower than the suggested amount. A well balanced, normal level calorie diet is just as healthy for your body currently and the future of your body. I know I almost immediately regret that extra cheeseburger, chinese food, or plate of fries with honey mustard. I also regret leaving the dining hall having only eaten a plate of salad. So the evidence from these studies offers good news! Eating healthy is obviously important, but to be healthy you don’t have to starve yourself. You also don’t have to run yourself to death in the gym to achieve a healthy physique and long life.