Can You Live Longer by Eating Less?

One area of scientific study that has been steadily pursued over a number of decades is the quality and length of the human lifespan. I mean, who wouldn’t want to live longer?

Recent research indicates the answer to slowing down the aging process might be to start following a calorie-restricted diet. Experts speculate that doing so can not only help people live longer but also be happier in the process.

How Does It Work?

The theory behind the idea that calorie restriction can help you live longer is that it can help prevent age-related conditions that harm the body by reducing free radicals and slowing down the metabolic rate. One study published in Cell Metabolism journal said that cutting calorie intake by 15% over the course of 2 years can help slow down aging and protect against diseases such as cancer, diabetes, and Alzheimer’s.

According to an associate professor of clinical sciences at Pennington Biomedical Research Center in Louisiana, Leanne Redman, Ph.D., who is also the co-author of this study, slowed metabolism has been found to increase the lifespan of hundreds of species of animals.

“Energy is handled more efficiently,” added Rozalyn Anderson, Ph.D., an associate professor at the University of Wisconsin School of Medicine and Public Health. “Pathways of resilience are triggered.”

The idea that what we eat must be used up or discarded isn’t new, and calorie restriction will help you do that. Fat, for instance, will be used up instead of being stored.

The idea of calorie-restricted diets isn’t new either, but studies have only been conducted on animals so far. This recent study was the first to shift its focus toward humans. 53 healthy, non-obese participants of ages between 21 and 50 were followed for a period of time. Researchers found that calorie-restricted diets can be beneficial even to those who were considered “healthy and lean”. They also found that many of the biomarkers for aging were reduced along with an overall improvement in health.

“One thing is certain,” said Anderson. “If you eat less and weigh less, you live longer.”


A more extreme version of this study was also conducted recently where a so-called “fasting-mimicking” diet was followed by the participants for five days per month for three months. The study, which consisted of plant-based foods such as vegetable soups and energy bars, had its results published in Science Translation Medicine and showed that this can also help reduce the effects of aging on the body.

Barry Sears, Ph.D., author of the Zone Diet book series and president of the Inflammation Research Foundation, explains that calorie-restricted diets work because it’s like cleaning the garbage out of your cells. “The more calories you eat, the more free radicals you generate,” he said. “They cause damage.”

Still, experts agree that there needs to be more research into the effects of calorie restriction in humans, although a lot of them can be understood from the studies conducted so far on animals.

One of them is an earlier study published in Nature Communications regarding monkeys who were found to be healthier when put on a calorie-restricted diet. Another study conducted at Washington University School of Medicine in St. Louis showed that some animals even lived up to 50% longer after a significant reduction in calorie intake. Therefore, researchers concluded that when such diets were followed by animals by midlife or earlier were able to live longer.

Energy Efficiency is Key

However, it’s not just about eating less. Energy efficiency is the most important thing to consider because food is the body’s fuel. That’s why experts worry that when it comes to calorie restriction, people may tend to be too extreme or do it the wrong way. This could lead to negative effects such as poor health, weakness, lethargy, loss of muscle mass, or bone density.

“You need fuel to be alive,” explained Anderson. “The vast majority of calorie intake keeps the ocean liner afloat.”

It gets trickier when you consider that there’s no one-size-fits-all diet. That’s why experts always advise consulting a doctor or nutritionist before starting any diet. Priya Khorana, EdD, a doctor of nutrition education at Teacher’s College, Columbia University says that cutting your calorie intake by 15% isn’t that drastic. However, she cautions against reducing your intake any more than that. Khorana says that combining a mild calorie restriction with exercise is the most effective way to stay healthy.

“In the long run, these diets aren’t as effective as modest diets,” Khorana explains “Following a balanced nutrient-rich diet is a key to success.”

Simply cutting back on calories without ensuring that you’re getting a healthy dose of essential vitamins and minerals would be detrimental to your health. In both the studies conducted on humans, they were asked to take vitamin supplements to make sure that their diets were still nutritionally rich.

So just cutting back on calories without getting good nutritional information could mean missing out on essential vitamins and minerals. In the two studies on humans, participants took vitamin supplements to make sure that their diets were still nutritionally rich.

A Final Word

It’s difficult to cut back on calories during a time where processed foods and sugar-laden treats are staring at you everywhere you turn, but experts agree that it is worth the effort. Healthy eating and energy efficiency are very important. Plus, according to Sears, diets can be successfully modified in as little as four days.

Ultimately, says Anderson, the aging process can be significantly influenced by what you choose to put in your body. “Diseases are all different,” she said. “But they’re all associated with aging. And calorie-restricted diets work.”

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