Search the web, and you’ll find any number of biohacking techniques for promoting healthy lifespan, from taking cold baths to breathing pressurized oxygen to sleeping under a red light.
There’s a simpler path to healthy aging, and science from Tufts and elsewhere has shown that it really works: Just eat a little bit less. Cutting down on calorie intake by as little as 10–15% can lower the risk of developing age-related illnesses by improving cardiovascular health, lowering blood pressure, and improving glucose tolerance, among many other benefits. For some people, reaping these benefits can be as easy as giving up one large latte per day.
The work is published in The American Journal of Clinical Nutrition.
“It doesn’t have to be some extreme measure,” says Sai Krupa Das, a senior scientist at the Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) at Tufts University, who is involved in the research to look at nutrition and lifestyle factors to promote healthspan, or the number of years someone remains healthy as they age.
“There are nutrition and lifestyle changes that can not only prevent chronic disease but also slow down the rate of aging.”
These findings come from a study called CALERIE, which stands for The Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy, that scientists from Tufts and elsewhere have been involved in for nearly two decades. The first phase of CALERIE ended 15 years ago, in 2011, and produced so much data that even today, Das and her colleagues are still publishing new findings based on this work.
During the initial phase of CALERIE, 143 participants attempted to reduce their caloric intake by 25% and then maintain that eating pattern for two years (the caloric restriction group) while another 75 participants continued eating as they normally would (the control group).
Periodically, both groups reported to one of three research centers involved in the study—HNRCA, Washington University, and Louisiana State University—for intensive testing covering many aspects of their physiology, from their weight to their blood pressure to their glucose tolerance.
Participants had to have “a wonderful mindset,” Das says. When they signed up for the study, they didn’t know whether they’d be placed in the dietary restriction group or the control group. They had to be both willing to make dramatic changes to their lifestyle and okay with not making those changes. “They had to be very good scientific citizens, and they were,” Das says.
Participants finished their two years of reduced energy intake in 2011, and the results were striking. Most people in the restricted group shifted their diets away from fats and toward protein and carbohydrates.
In the end, they only cut their calories by about 12% rather than the 25% the researchers had hoped for, but still their blood pressure, LDL-C (“bad”) cholesterol, and insulin levels dropped markedly compared to the control group. Weight loss was not the goal of the study, but nonetheless, participants’ weight dropped by about 10%.
“The most exciting part is that we saw these benefits with only a moderate level of restriction that’s feasible for most people,” Das says. “And that was in a healthy population without obesity. When we apply this to people with overweight or obesity, we expect the outcome to only get better.”
The researchers are still publishing their findings from the study today. In a publication that came out earlier in 2026, they showed that restricting calories didn’t compromise the nutritional quality of participants’ diets.
The restricted group took a multivitamin and a calcium supplement to make sure they were getting all the nutrients they needed, but their food diaries showed that they would have been fine even without these precautions.
Why caloric restriction has health benefits is still not completely clear, but it seems that eating less primes the body to convert food into cellular energy without producing a lot of reactive oxygen species: unstable molecules that damage cells, contributing to a wide range of health problems from cancer to Parkinson’s.
A urine test confirmed that participants in the caloric restriction group had lower reactive oxygen species levels than those in the control group.
CALERIE isn’t done yet. Recently, the researchers invited all the participants to come back into the lab for a follow-up study to see whether the early changes they made to their lifestyles still have positive impacts on their health over a decade later.
Surveys will also reveal whether participants continued to restrict their calories after the study ended, when they were left to their own devices. Das and her colleagues have completed the data collection for this phase of the project and are beginning to conduct the analysis.
“I think the follow-up was necessary simply because we found such wonderful results in the primary study, and it is important to understand what the longer-term impacts are,” she says.
Meanwhile, many adults can safely get the benefits of moderate caloric restriction on their own, without taking part in an intensive study. There are some exceptions, such as people over age 65, young children, pregnant people, those with a body mass index under 22, and anyone who has bone density loss or a specific disease that requires medication.
These groups should consult with their doctor before reducing their calorie intake. But for an average person who’s relatively young and healthy, Das says it’s easy to get started on your own.
“There are online tools that you can use to calculate how many calories you’re currently eating per day. Use that, and then take off 20%, or even just 10%,” she says.
A decadent chocolate chip cookie contains about 200 calories, so for someone who eats a 2,000-calorie diet (which is about what’s recommended for women), cutting 10% might be as simple as skipping a daily dessert. Sugary coffee drinks can also be surprisingly high in calories, so cutting some of these out can be another good starting point.
People can spread out the calorie cuts over the course of a week in whatever way works best for them. Some people prefer to restrict calories to only two days of the week: a diet known as 5:2 intermittent fasting.
Whether it’s best to continue caloric restriction indefinitely or do it for a set period of time, like in the study, is an open question. Go with how you feel, Das says. If you start to drop into the underweight range, or you feel lightheaded or low energy, those could be signs it’s time to recalibrate and see what is healthy for you.
And keep in mind: “You don’t have to shoot for crazy numbers, like the 30% or 40% restriction. Even 10% is very helpful,” Das says. The benefits are especially important as medical advances extend the human lifespan, she adds. Those extra years won’t be much fun if they’re not years spent in good health. https://medicalxpress.com/news/2026-05-staying-healthy.html
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