If you’ve heard the words “intermittent fasting” recently, you’re not alone. Intermittent fasting, is a type of eating pattern, which has gained significant attention in recent years. But is it just another fad diet, or could it offer real benefits for seniors? Like other diets, there are benefits and risks, so consider your own personal health situation and talk with a CenterWell primary care doctor before changing your eating habits.

Now let's take a closer look at intermittent fasting for seniors and how it works.

Intermittent fasting is an eating pattern based on time restrictions, not avoiding specific foods. You cycle between periods of eating and periods of very low or no caloric intake, which is considered the fasting period. During the designated time as the eating window, you consume a typical diet. It is important to remember that intermittent fasting is not a diet in the traditional sense, but rather a strategic approach to when you eat, not what you eat.

There are several ways to start, but they all involve regular periods of eating and fasting. Some common methods include:

• Time-restricted eating: Limiting your eating to a specific window each day, such as 8 hours, and then fasting for the remaining 16 hours. This is often referred to as the 16/8 method.¹
• Full-day fasting: Eating a normal diet one day and either consuming no calories or a very small number of calories (around 25% of your usual intake) on alternate days. A popular version of this is the 5:2 diet.¹
• 5:2 pattern: Eating regularly for 5 days a week and limiting yourself to one 500–600 calorie meal on the other 2 days.¹ This allows for more flexibility while still incorporating fasting periods.
• Eat-stop-eat: This involves a 24-hour fast once or twice a week. For example, you might eat dinner one day and then not eat again until dinner the next day.⁵

Mark Mattson, a neuroscientist at Johns Hopkins University, says that when you go without food for a while, your body uses up all its sugar for energy. Then, it starts burning fat for fuel instead. He calls this change "metabolic switching."

This is different from how many people eat. Most people snack and eat meals throughout the day. When that happens, the body mostly uses the easy-to-get calories from the food that was just eaten. It doesn't really need to burn any stored fat.

This switch from burning sugar to burning fat is a big reason why intermittent fasting (eating only during certain times) might be good for you especially if you need to burn fat.

When starting any new dietary routine, there are always questions of safety or if the benefits are worth the change. Research suggests that intermittent fasting may offer several health benefits, particularly in the short term.¹

• Improved blood sugar levels: May improve insulin sensitivity and help the body regulate blood sugar more effectively. This is particularly important for seniors who may be at risk of developing type 2 diabetes.
• Weight loss: May help reduce overall caloric intake, leading to weight loss. If you are a senior struggling with losing weight or obesity, this may help.
• Lower blood cholesterol: May lower LDL cholesterol and triglycerides, reducing the risk of heart disease.
• Reduced blood pressure: May help lower blood pressure, another important factor in cardiovascular health.
• Decreased chronic inflammation: May reduce markers of inflammation in the body, which is linked to many chronic health diseases.
• Brain health: May boost working memory and verbal memory.

While intermittent fasting can be promising, it is not without potential risks, especially for seniors. It is important to consider these factors and follow up with your CenterWell primary care doctor about your personal health situation and future goals.

• Limited long-term data: More research is needed to fully understand the long-term impact on overall health and longevity.¹
• Varied results: Some studies suggest that by simply limiting calories may provide the same benefits of intermittent fasting.¹
• Potential heart disease risk: Some evidence shows that a 16-hour fast with an 8-hour eating cycle may raise heart disease risk compared with other time-restricted eating cycles.¹
• Side effects: Seniors may experience side effects such as tiredness, dizziness, headaches, mood swings, or constipation.
• Muscle loss: It is important to ensure adequate intake of protein during the eating window to prevent muscle loss, which is a concern for older adults. Sarcopenia, the age-related loss of muscle mass, is a concern for seniors, and adequate protein intake is crucial to mitigate this risk.⁸
• Medication interactions: Seniors often take multiple medications, so this is a critical consideration because intermittent fasting may affect how the body processes and metabolizes the medication taken.

Intermittent fasting is not for everyone. It is important for seniors to think about and consider their own personal health, any chronic conditions they may have or daily living routines that may make intermittent fasting for seniors more challenging for them. Seniors should talk with their family or caregivers as well if considering trying intermittent fasting or any other new eating routines. If you have any of the below conditions, you should avoid intermittent fasting.³

• An eating disorder
• High risk of bone loss and falls
• Diabetes, especially if you are insulin dependent
• A history of hypoglycemia (low blood sugar)
• A serious medical condition, such as kidney disease or liver disease
• History of malnourishment

By age 50, women typically struggle with stubborn weight gain, especially around the waist and midsection which also makes you more prone to developing insulin resistance and Type 2 diabetes. Losing weight for middle-aged and senior women can be frustrating, so finding an eating routine like intermittent fasting that can help drop the extra pounds and prevent chronic health conditions becomes a priority.

Why is intermittent fasting different for women than men? The reason is hormones. During childbearing and perimenopausal years, hormone levels may shift even more. Intermittent fasting can have a negative effect on progesterone, estrogen and affect hormones in several ways, including:⁴

• Change hormone levels which are regulated by gonadotropin
• Changes in hormones affects ovulation for younger women
• Hot flashes
• Night sweats
• Headaches
• Lower sex drives
• Dry skin

While ovulation and pregnancy may not be a reality for senior women, intermittent fasting may still lower hormone levels, which women over 50 need to be aware of.

Intermittent fasting for men over 50 has the same benefits as for younger men, including weight loss and the potential for better brain health over time. However, as mentioned, the studies are not clear as to the exact risks or benefits—so know your own health and personal limitations before trying intermittent fasting.

Men over 50 who have chronic health conditions or a weakened immune system should exercise caution, especially if they have diabetes or are taking heart or blood pressure medications. Our CenterWell primary care doctors can help men over 50 decide what diet or eating routine is safest for them.⁵

As mentioned earlier, intermittent fasting is not a diet that tells you what to eat or what not to eat, but when to eat. For seniors, eating nutritious foods to help support and maintain overall health and strength is important. The Mediterranean diet is a great model to follow because of the health benefits of the food choices consumed. This diet focuses on leafy greens, healthy fats, lean proteins, and complex carbohydrates like whole grains. Here are some ideas for the best foods to eat:

• Lean proteins: Chicken, fish, beans, lentils, tofu
• Fruits: Berries, apples, bananas, oranges
• Vegetables: Broccoli, spinach, carrots, peppers

Before starting any new dietary regimen, especially intermittent fasting, it is essential to consult with your healthcare provider. It may take some time for your body to adjust to intermittent fasting. Start slowly and gradually increase the length of your fasting periods over time.

These 5 key tips are critical to consider:

• Drink plenty of water, tea, or coffee (without added sugar or cream) during fasting periods.³
• Pay attention to how you feel and adjust your fasting schedule as needed. If you experience any negative side effects, stop intermittent fasting and consult your doctor immediately.
• Start with a 10-12 hour overnight fast rather than a longer 16-hour fast.³
• Ensure you eat enough protein during eating windows to prevent muscle loss.
• Consider taking a multivitamin as a supplement to food.

Intermittent fasting for seniors may offer some health benefits, but it's not a one-size-fits-all approach. Carefully consider your own potential risks and focus on nutrient-dense foods. Always consult with your primary care doctor before making significant changes to your diet.

Content contained on this page is for informational purposes only and does not constitute medical advice. Always consult your healthcare provider before starting any new fitness or dietary plan. References are provided for informational purposes only and do not imply endorsement of any website or other sources. For any health-related questions, contact your healthcare provider.

• Mundi, M.D., Manpreet. “What Is Intermittent Fasting? Does It Have Health Benefits?” Mayo Clinic, last accessed May 5, 2025, https://www.mayoclinic.org/healthy-lintermittent fastingestyle/nutrition-and-healthy-eating/expert-answers/intermittent-fasting/faq-20441303
• "Intermittent Fasting: What Is It, and How Does It Work?" Johns Hopkins Medicine, last accessed May 5, 2025, https://www.hopkinsmedicine.org/health/wellness-and-prevention/intermittent-fasting-what-is-it-and-how-does-it-work
• Chien, Shanley, et al. “Foods to Eat During Intermittent Fasting (and What to Avoid)." U.S. News & World Report, last accessed May 5, 2025, https://health.usnews.com/wellness/food/articles/intermittent-fasting-foods-to-eat-and-avoid
• “How Intermittent Fasting Affects Women,” Cleveland Clinic, last accessed May 8, 2025, https://health.clevelandclinic.org/intermittent-fasting-for-women
• Caroline Lamber, “Intermittent Fasting for Men Over 50: Benefits, Possible Risks, and 10 Tips to Boost the Advantages,” BetterMe, last accessed May 8, 2025, https://betterme.world/articles/intermittent-fasting-for-men-over-50/#Is_Intermittent_Fasting_Good_for_Men_over_50