Intermittent Fasting for People Over 50

“The first week will be a little hard,” says Satchin Panda a professor in the Regulatory Biology Laboratory at the Salk Institute for Biological Studies in San Diego. “You will feel a bit hungry.” But over time, the pattern should feel comfortable. If it’s too challenging, practice the method just five days a week at first and gradually work up to seven days.

To make the most of time-restricted eating, Panda says, your last meal of the day should be three hours before you go to bed to aid digestion and optimize sleep. The next morning, “wake up, wait two hours, and then have your first calorie,” he says. That helps sync with your circadian clock.

Try these tips when getting started:

• Use reminders such as a cell phone timer to tell you when your eating window is opening and closing. Timers can help you remain consistent.
• Avoid breaking your fast with a heavy meal: Opening your eating window with a large meal can throw off your satiety hormones, making the next fasting period harder. Start with hydration, such as water or milk mixed with protein powder and later move on to a protein-based snack, suggests Kenneth Koncilja, an internal medicine physician at the Cleveland Clinic’s Center for Geriatric Medicine.
• Plan your main meal later in the day—break your fast around 2 p.m. then schedule dinner around 6 p.m. to align with family mealtime.

Risks of intermittent fasting

While intermittent fasting may offer benefits, it also carries risks for older adults—especially those with existing health conditions.

 “If someone has medical conditions like hypertension or diabetes, they might want to work with their primary care physician to develop a strategy that is more individualized,” says Koncilja.

Here are a few conditions that he said may require special considerations:

• Cancer: Individuals undergoing treatment may need higher protein and calorie intake, which can be difficult to achieve with time-restricted eating.
• Hypertension: Fasting may increase the risk of orthostatic hypotension, a condition where blood pressure drops with changes in position, leading to dizziness or lightheadedness.
• Diabetes: Going long periods of time without eating can disrupt insulin secretion and glucagon storage, making blood sugar harder to manage. If you have diabetes, intermittent fasting can be risky. Consider medical supervision to ensure it’s done safely and effectively, says Koncilja. He recommends using a continuous glucose monitor (CGM), which helps track how the body responds to different “food choices, environments and activities—including time-restricted feeding.”

Other common risks for older adults:

• Inadequate protein intake: A common issue with intermittent fasting is not getting enough protein during eating windows, which can lead to sarcopenia (muscle loss) and osteopenia (bone loss). Make sure to track your protein and read nutritional information.
• Dehydration and electrolyte imbalance: Clean fasting —allowing only zero-calorie drinks—can make it harder to stay properly hydrated and maintain electrolyte, raising the risk of orthostatic hypotension—dizziness or lightheadedness when standing up.
• Muscle loss: Experts stress that any fasting routine should be accompanied by exercise. “People who become inactive quickly lose muscle mass,” says Panda, whose research demonstrated that intermittent fasting improves cholesterol and blood pressure in firefighters. He recommends brisk walking 30 to 45 minutes every day and simple strength training exercises to maintain your muscle — a particular concern for older individuals.
• Take medications with food: Some medications must be taken with meals to avoid nausea or stomach irritation.
• Use heart or blood pressure medications: These can affect potassium and sodium levels, which may be further disrupted by fasting.
• Have a history of eating disorders: Fasting can trigger disordered eating patterns and should be approached with caution.

Make fasting safer by:

• Talking to your primary care provider about your approach
• Tracking your carbohydrates, fats and proteins to ensure you are getting the amount your body needs.
• Know that most studies show that fasting does not cause hypothyroidism and won’t worsen existing thyroid problems

Benefits of intermittent fasting

While fasting may sound extreme. Is it safe for people over 50? The answer seems to be mostly “yes,” and there’s a lot to recommend it.

“In studies of one to two years, we’ve seen weight and fat loss, metabolic health improvements, particularly [type 2] diabetes, and improvements in memory and physical function,” says Sai Das, a senior scientist on the Energy Metabolism Team at Tufts University’s Human Nutrition Research Center on Aging, who has studied the strategy. 

Most are successful and see results: For instance, in a recent study in the journal, Experimental Gerontology, 108 overweight men and women, 65 to 74, either practiced six weeks of time-restricted eating or got educational materials. The vast majority of the fasting group was able to avoid eating for 16 hours (from 8 pm to 12 noon the following day). That group significantly lowered their body mass index, or BMI, without decreasing their bone density, which can be a risk when losing weight. Men in the study also saw a significant reduction in waist circumference and visceral fat — the fat around the abdominal organs. And a large meta-analysis of 23 studies involving overweight or obese people up to their early 70s found that a variety of intermittent fasting approaches significantly reduced waist circumference and fat mass, plus levels of insulin, fasting glucose, total and LDL (bad) cholesterol and triglycerides, a particularly dangerous type of blood fat at high levels. Other studies suggest intermittent fasting can quell inflammation, which fuels many chronic diseases and cancer.

Cognitive support: Inflammation is a potential culprit in dementia as well. And new data reported in 2024 in Cell Metabolism suggest that strategic fasting may defend the brain against cognitive decline. “This was the first study in humans to look at the effects of intermittent fasting on cognition and the brain,” says study author Mark Mattson, adjunct professor of neuroscience at the Solomon H. Snyder Department of Neuroscience at Johns Hopkins School of Medicine in Baltimore. In the study, 40 people ages 55 to 70 were assigned either to the 5:2 fasting plan or to a generally healthy diet. The fasting group lost more weight, plus they saw greater improvements on tests of executive function and memory.

Cellular rejuvenation: Although most people who try intermittent fasting do so to shed pounds, there are clearly other perks that seem to be independent of the weight loss. “Even without weight loss, we think that this type of restricted eating can contribute to the metabolic fitness of cells,” says Miriam Merad, M.D., chair of immunology and immunotherapy at the Mount Sinai School of Medicine. That means cells appear healthier and even biologically younger in people following this type of diet, as reported in a study in Nature Communications in 2024.

Longevity and inflammation control: Changes at the cellular level, not all of which are understood, seem to produce the positive outcomes associated with intermittent fasting. For example, fasting raises levels of a chemical in the body that activates longevity genes known as sirtuins. Sirtuins protect against disease, boost the repair of DNA, and quell the inflammation behind arthritis, atherosclerosis, asthma and other chronic conditions.

Circadian rhythm and digestion: Intermittent fasting supports the body's circadian clock, says Panda, which regulates the body's sleep/wake cycle. “Repair happens during sleep,” he says. It takes about five hours to digest the last meal of the day. “If dinner is at 6 p.m., the gut is still working until 11 pm. Downtime for repair happens after that. The gut needs seven hours of downtime” for repair. This schedule also supports healthy insulin levels, important for diabetes risk.

One study that got lots of attention in early 2024, but hasn’t been peer-reviewed or published yet, suggested that intermittent fasting may cause heart problems. But it’s been widely questioned as being a look-back study based on only two days of self-reported food logs.

Results in adults with obesity: Most recently, a 2025 study in Nature Medicine found that 8-hour time-restricted eating led to weight loss and improved health in adults ages 30 to 60 with obesity, compared to a Mediterranean diet, regardless of meal timing. The results suggest time-restricted eating is an effective dietary strategy, though more research is needed in diverse populations.