Why Is Calorie Restriction Good For Longevity?

Longevity 120 is a community-supported website. We may earn a small commission on purchases made through our links. Learn more.

Aging brings with it a plethora of ailments such as loss of vision, hearing, memory and mobility, neck pain, back pain, depression and diabetes.

And, the best way to live a healthy and long life is to reduce the risk of developing health conditions such as heart disease, diabetes, cancer, etc.

If you’re looking for ways to increase your lifespan and enjoy your older years with good health, youthfulness and vigor, then research shows that calorie restriction may be a comprehensive and effective way to slow the effects of aging and solve most ailments that come with it.

In this article, we’ll explore why calorie restriction is good for longevity and how it works. But before we go on to discuss this, it is important to understand what calorie restriction is.

What Is Calorie Restriction?

Calorie restriction essentially involves the reduction of your diet to less than what you regularly eat, while maintaining sufficient intake of all the macro and micronutrients required for the healthy functioning of your body.

Depending on the protocol you are following, the calorie restriction varies, but it generally means reducing the daily calorie intake by around 10%.

It has been seen that calorie restriction can help with weight loss, but when taken to extremes, the calorie restriction can cause serious health problems.

Calorie Restriction Research

Research on calorie restriction and longevity dates way back to 1935, when Clive McCay, a scientist from Cornell discovered that rats that were on a calorie-restricted diet lived almost 30% longer compared to those that were on normal diets.

Ever since, there has been a body of research conducted on the impact of calorie-restricted diets on mice, worms, guppies, flies, spiders, primates and dogs.

According to the National Institute on Aging, there are two ways by which a calorie-restricted diet increases lifespan. Firstly, the production of free radicals or the highly damaging forms of oxygen is reduced. 

Secondly, the resistance of cells to stress is increased by calorie restriction. And, both these are vital in protecting against several diseases such as cardiovascular diseases, and cancers that negatively impacts the lifespan and reduces it.

It has also been seen that a calorie-restricted diet can affect several processes that can regulate the rate of aging including inflammation, metabolism of sugar, capability to provide energy for cellular processes, maintenance of protein structures, modification to the DNA, etc.

It also helps to improve blood sugar levels and reduce cholesterol levels in animals. Calorie restriction also affects another process, i.e., oxidative stress, which is essentially the toxic by-product that is produced when oxygen is metabolized and causes damage to the cells and tissues in the body.

But the important question is, “does calorie restriction benefit humans?”

Why Is Calorie Restriction Good For Longevity

As you can see, there is plenty of evidence supporting the benefits of a calorie-restricted diet in mice and rats. The argument is that since they have the same physiology as humans, it is assumed that calorie restriction can have the same impact on humans too.

In fact, there are many research studies such as CALARIE (Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy) that are studying cells and metabolism to explain how calorie restriction can help to extend lifespan.

In the CALARIE clinical trial, a group of more than 200 people aged between 21 and 50 years was assessed over two years. All the participants in the trial had a BMI (body mass index) of around 22 to 27.9 and belonged to the healthy, non-obese category.

The trial showed that the health of the participants improved significantly, there was a reduction in the cardiometabolic factors involving blood pressure and cholesterol levels in the group and the biomarkers for aging reduced.

But the genes, as well as the processes controlling metabolism are rather complex and there is a long way to go in understanding the complete picture.

Effects Of Calorie Restriction

What we know about calorie restriction is that when you reduce the number of you eat, you tend to lose weight. There is plenty of research showing that excess body fat can be dangerous to health in the long run, in various ways.

measuring the waist

And, even a little bit of increase in weight can cause several age-related problems including diabetes, Alzheimer’s disease, cancer, etc.

One of the main factors that contribute to this is the link between fat cells and chronic inflammation. So, in short, you can say that being overweight can cause you to have a less healthy and a shorter life.

So, calorie restriction-related health benefits probably stem from the loss of fat and other aspects that control metabolism.

For instance, calorie restriction boosts autophagy, the process by which cells remove damaged parts and recycle the materials into new parts.

Research shows that when damaged components of cells are left, over time, they cause problems and contribute to age-related decline. They also damage the rest of the body. And, so increased levels of autophagy can help to reduce aging and extend lifespan.

According to the CDC, an average male in the US eats around 2,745 calories and an average female consumes around 1,833 calories per day.

And, when you follow a calorie-restricted diet, this calorie consumption is reduced by more than 1/3rd over time. So, when we say “calorie restriction”, what does it really mean?

According to the website of the Calorie Restriction Society, the premise of calorie restriction is to eat fewer calories but not consume fewer minerals, vitamins and other components constituting a healthy diet.

By doing this, you can achieve a healthier, as well as longer life. And, there is evidence to show that this calorie restriction, along with regular exercise, offers many health benefits, as well as adds to the quality of life and increases lifespan.

How Do Calorie-Restricted Diets Work?

Calorie-restricted diets are seen to offer several benefits. These diets may help to defend your body against age-related diseases, improve mood and are often used by people as a tool to increase their lifespans.

According to a study in the Cell Metabolism journal, cutting calorie consumption by 15% over more than two years can protect against many diseases like diabetes, Alzheimer’s and cancer and also slow down aging.

These calorie-restricted diets slow down the metabolic rate and also reduce the free radicals that are linked to chronic illnesses. In animals, it is seen that slowed metabolism is linked to a longer life.


In calorie-restricted diets, energy is used more efficiently, triggering the pathways of resilience and instead of storing fat, the body uses it.

A study involving an extremely calorie-restricted diet showed that when diets mimicking fasting, including plant-based foods such as vegetable soups and energy bars were practiced for five days a month for a period of 3 months, it helped the body to reduce aging.

And, these calorie-restricted diets work because garbage is cleaned out from the cells because the more calories you consume, the more free radicals that are produced and the greater the damage caused.

But energy-efficiency is vital when it comes to calorie-restricted diets. Cutting back too many calories drastically or in the wrong way can cause reductions in bone density and muscle mass, which can cause more harm than good.

Reducing calorie intake by around 15% may not be too drastic, but a 25% restriction is not healthy. And, simply cutting back on the calories without good nutrients i.e., vitamins and minerals, are not effective.

The key to an effective and successful diet is to follow a balanced diet that is rich in nutrients along with regular exercise.

If you’re cutting calories but not paying attention to your nutrition, this may lead to severe health consequences such as affecting your bones, immune system and the ability to concentrate and focus.

The calorie-restricted diet must contain vegetables, fruits, whole grains, legumes and lean protein sources like poultry, fish, lean red meat and eggs. And, irrespective of the number of calories you cut, you cannot get out of exercise or physical activity.

Healthy eating, along with the efficient use of energy is the key to longevity. In short, calorie-restricted diets are effective in delaying aging and reducing the incidence of diseases related to aging.

Why Is Calorie Restriction Good For Longevity: Conclusion

In conclusion, there is ample research to show that calorie restriction can have anti-aging benefits and can play a very important role in reducing aging-related diseases and enhancing longevity.

You may be tempted to try a calorie-restricted diet, but it is important to understand the pros and cons of such a diet and speak to your medical practitioner before you embark on one and make any major changes to your eating pattern.

Rosemary Richards