Whether you’ve overindulged a little too much lately, or if you are already restricting your calorie intake to lose weight or feel healthier, eating less is about so much more than simply losing unwanted bodyfat. Calories are our life fuel and influence everything from energy to muscle mass, so determining how many to drop in order to feel better in ourselves is a confusing issue. Fortunately, one important experiment has shown the number of calories you can forego and potentially live a longer and healthier life, and it’s less than you might think.

Scientists have long thought that reducing our overall calorific intake, at least from time to time, is a great way to delay the progression of age-related diseases and promote heart health. And, while numerous studies have backed up this theory using animals as subjects, recent studies with humans appears to confirm that these same benefits can be enjoyed by us, too. Researchers used data taken from individuals participating in a project known as CALERIE (Comprehensive Assessment of Long-Term Effects of Reducing Intake of Energy). For two years, participants were asked to reduce their total calories by 25%, but in reality, the average number of calories dropped came out lower.

Hungry man eating tuna with a fork
Zhanna Fashayan

How Many Calories Should We Eat to Get Healthier?

As it turned out, the study participants were only able to reach a reduction of 12% as a group. While this wasn’t enough to activate all of the potential benefits that are thought to come from calorie restriction, the results were still promising. “A 12% reduction in calorie intake is very modest,” said Luigi Ferrucci, M.D., Ph.D., who is the corresponding author of the report, and NIA Scientific Director. “This kind of small reduction in calorie intake is doable and may make a big difference in your health.”

Scientists monitored the subjects at regular intervals and analyzed the resulting molecules that code for proteins by taking muscle samples. They were able to determine that this subtle level of calorie restriction upregulated the genes responsible for energy formation and metabolism, while downregulating genes that are responsible for inflammation. “Since inflammation and aging are strongly coupled, calorie restriction represents a powerful approach to preventing the pro-inflammatory state that is developed by many older people,” said Ferrucci. It is thought that a restriction of 25% would see even greater improvements in these areas, and rodent studies have gleaned great results from a 40% reduction, but 12% was enough to get things going in the right direction.

With the number of calories being consumed on rise, thanks to fast and ultra processed foods, it is thought that the average American now munches through upwards of 3,600 per day. The USDA, however, recommends an upper limit of 2,400 calories for women (19-30) and 3,000 calories for men (19-30), going down further as we age. It appears then, that many of us could easily drop 12% without too much trouble, and feel all the better for it.

Important to note is that while the participants did reduce their overall calorie intake, they still ate enough minerals and nutrients to meet their various macro and vitamin requirements. Significantly dropping calories can reduce muscle mass size, but reassuringly, strength is maintained according to some studies But always remember; before making any significant changes to your diet, consider seeking medical advice.

Additional information on this study can be found here!