Time-Restricted Eating Works the Same Before and After Menopause: What the Research Shows

Time-Restricted Eating Works the Same Before and After Menopause: What the Research Shows

Researchers tested a daily eating window of 4 to 6 hours in 32 women with obesity. Some women were premenopausal. Some were postmenopausal. After 8 weeks, both groups lost about the same amount of weight — around 3 percent. The study found this eating pattern works the same no matter your menopause stage.

Medical disclaimer: This article summarises published research for informational purposes only. It is not medical advice and is not a substitute for guidance from a qualified health professional. Always consult your doctor before starting any fasting protocol, especially if you have an existing health condition or take medication.

The Short Version

• What they tested: Whether eating in a short daily window works differently before or after menopause.
• Who did it: S. Cienfuegos and team at the University of Illinois at Chicago, published in Experimental Gerontology in 2021.
• How many people: 32 women with obesity — 13 were premenopausal and 19 were postmenopausal.
• How long: 8 weeks.
• What happened: Both groups lost about 3 percent of their body weight, with no real difference between them.
• Read the study yourself: Experimental Gerontology 2021 →

What They Wanted to Find Out

Many women wonder if fasting works differently once their hormones start changing. This study asked a simple question. Does eating only within a short window each day help premenopausal and postmenopausal women the same way? The researchers already knew the eating pattern helped with weight. They wanted to know if menopause status changed the result. You can read more about how time-restricted eating affects menopause symptoms and whether it changes women's hormones.

Who Was in the Study

Who they were: All 32 women had obesity. The study only included women — men were left out. Women who were in the middle of the menopause transition, called perimenopause, were not included at all.

What the fasting actually looked like: Women ate only during a window of 4 to 6 hours each day. For the other 18 to 20 hours, they did not eat. This is a form of time-restricted eating. It ran for 8 weeks.

What Happened

Both groups lost about the same amount of weight — roughly 3 percent of their starting body weight.

• Fat mass dropped in both groups by similar amounts.
• Lean mass, which includes muscle, organs and water, also went down slightly in both groups.
• A specific muscle measurement did not drop in either group.
• Fasting insulin levels fell in both groups by similar amounts.
• A marker of cell stress in the blood also dropped in both groups.
• Women stuck to their eating window well. Both groups managed it on about 6 out of 7 days each week.

What Did Not Change

• A measurement of deep belly fat stayed the same in both groups.
• Blood pressure did not change in either group.
• Cholesterol numbers stayed about the same in both groups.
• Triglycerides, a type of blood fat, did not change.
• Blood sugar levels and a 3-month blood sugar average stayed the same.
• Two markers linked to body-wide swelling did not change in either group.

What the Researchers Said

The researchers concluded that this eating pattern helps with weight and health markers the same way, no matter a woman's menopause stage. Being premenopausal or postmenopausal did not change the outcome.

What This Means for You

• If you are premenopausal or postmenopausal: This study suggests the eating pattern can work for you either way.
• If you are worried about muscle loss: A specific muscle measurement did not drop in either group here.
• If you are in perimenopause: This study cannot speak to you directly. Women in that stage were left out.
• If you want steady results: Both groups stuck to their eating window most days of the week, which suggests it is workable long term.
• If you want more detail on menopause and fasting: See how a different study measured menopause symptoms during time-restricted eating.
• If you are curious about muscle and fasting in general: Read about fasting and muscle in older adults.

What This Study Could Not Tell Us

• Only 32 women took part. That is a small number.
• Every single person in the study was a woman, but perimenopausal women were left out entirely.
• The study ran for 8 weeks. It cannot say what happens after a year.
• Everyone in the study had obesity. Results may look different for women at other weights.
• The way sticking to the plan was recorded is not stated in the abstract.
• Funding came from the National Institutes of Health, based on the study record.

The Study Details

Cienfuegos, S., Gabel, K., Kalam, F., Ezpeleta, M., Lin, S., & Varady, K. A. (2021). Changes in body weight and metabolic risk during time restricted feeding in premenopausal versus postmenopausal women. Experimental Gerontology. PMID: 34478825

Common Questions

Does intermittent fasting work differently after menopause?

This study found no real difference. Premenopausal and postmenopausal women both lost about 3.3 percent of their body weight in 8 weeks.

Does time-restricted eating cause muscle loss in women?

In this study, a specific muscle measurement did not drop in either group. Total lean mass, which includes more than just muscle, did go down slightly.

What eating window did the women in this study use?

They ate all their food within 4 to 6 hours each day. The other 18 to 20 hours were fasting time.

Was this study done on perimenopausal women?

No. Women in the middle of the menopause transition were excluded from this study entirely.

How much weight did women lose with time-restricted eating in this study?

Both groups lost about 3.3 percent of their starting body weight over 8 weeks. There was no meaningful difference between the two groups.

More Research Like This

• Time-Restricted Eating Eased Menopause Symptoms More Than Exercise
• Does Time-Restricted Eating Change Women's Hormones? No
• Combining Fasting With Interval Workouts Helped Women Over 50 Get Fitter
• Time-Restricted Eating Does Not Reduce Bone Density in Seven Trials
• Does Intermittent Fasting Help Menopause Night Sweats?
• Alternate-Day Fasting Improved Premenstrual Mood and Quality of Life in Overweight Women
• 16:8 Fasting Reduces Body Fat and Visceral (the fat around the organs) Fat in Older Men — While Preserving Muscle Mass

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