Time-Restricted Eating Cuts Weight the Same in Both Menopause Stages: What the Research Shows

Time-Restricted Eating Cuts Weight the Same in Both Menopause Stages: What the Research Shows

Researchers at the University of Illinois at Chicago studied 32 women with obesity for 8 weeks. All of them ate food only within a 4 to 6 hour window each day. Thirteen women were before menopause. Nineteen were after it. Both groups lost about 3 percent of their body weight. Menopause status made no real difference to the results.

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 time-restricted eating (food only in a short daily window) works the same before and after menopause.
• Who did it: Sofia Cienfuegos and team at the University of Illinois at Chicago, published in Experimental Gerontology in 2021.
• How many people: 32 women with obesity — 13 before menopause and 19 after it. Exact ages were not stated in the abstract.
• How long: 8 weeks.
• What happened: Both groups lost about 3 percent of their body weight, with no meaningful difference between them.
• Read the study yourself: Experimental Gerontology 2021 →

What They Wanted to Find Out

Many women wonder if fasting stops working once periods change or stop. This study asked exactly that question. Researchers wanted to know if a short daily eating window helps women the same way. Does it matter if she still has periods, or has gone through menopause?

It builds on other work, like this study on time-restricted eating and menopause symptoms. The women in this study did not skip meals randomly. They picked a set window each day, just 4 to 6 hours. They ate all their food inside it. For the rest of the day, they fasted.

Who Was in the Study

Who they were: All 32 women had obesity. None were in the switch-over years of perimenopause. Those women were left out of this study on purpose. Exact ages were not stated in the abstract.

What the fasting actually looked like: Each woman picked her own 4 to 6 hour window. She ate all her food inside it. For the other 18 to 20 hours, she fasted. This ran every day for 8 straight weeks.

What Happened

Both groups lost almost the same amount of weight — about 3 out of every 100 pounds they started with.

• Weight dropped by a similar amount in both groups. There was no real difference between them.
• Body fat went down by a similar amount in both groups.
• Fasting insulin, a sign of how the body handles sugar, improved in both groups.
• Insulin resistance, meaning how hard the body works to use insulin, got better too.
• A marker of cell wear and tear, called oxidative stress, dropped in both groups.
• Women in both groups stuck to their eating window about 6 out of 7 days each week.

What Did Not Change

• Muscle mass stayed the same in both groups. No muscle was lost.
• A separate muscle-amount measurement did not change either.
• Blood pressure stayed about the same in both groups.
• Cholesterol numbers, both the good and bad kinds, did not change.
• Triglycerides, a type of blood fat, stayed steady.
• Blood sugar and a longer-term blood sugar test both stayed the same.
• Deep belly fat, the kind wrapped around organs, did not change.
• Two markers linked to body-wide swelling and irritation stayed steady too.

What the Researchers Said

The team found that menopause status did not change how well time-restricted eating worked. Weight loss and health improvements were similar whether women were before or after menopause.

What This Means for You

• If you are past menopause: This study suggests fasting can work just as well for you as for younger women.
• If you have not reached menopause yet: You may see a similar amount of weight loss.
• If you are in perimenopause (the years right before periods stop): This study cannot tell you what happens. Those women were left out. See what another study found on fasting during menopause instead.
• If you worry about losing muscle: Good news. No muscle was lost in either group here.
• If you want a simple plan: Both groups just picked one window, 4 to 6 hours, and stuck to it most days.
• If you want more on hormones: This study on fasting and women's hormone levels looked at that question directly.

What This Study Could Not Tell Us

• It only included 32 women, so results may not hold for everyone.
• No perimenopausal women took part. They were excluded from the start.
• It ran for just 8 weeks. It cannot say what happens after a year.
• Everyone in the study had obesity. Results might differ for women at a lower weight.
• No men were included, so there is nothing to compare fasting effects between sexes here.
• The abstract does not report how many women dropped out along the way.

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 time-restricted eating work differently after menopause?

No. This study found weight loss was almost identical, about 3 percent, in women before and after menopause. Menopause status did not change the result.

Can women in perimenopause use this study to guide fasting?

Not directly. Perimenopausal women were left out of this trial on purpose. A different study looked at fasting during menopause symptoms instead.

Does time-restricted eating cause muscle loss in women?

Not in this study. Muscle mass stayed the same in both groups after 8 weeks. A separate muscle-amount test also showed no change.

How long did the women fast each day?

They ate all their food within a 4 to 6 hour window. For the remaining 18 to 20 hours, they fasted.

Did the women stick to the eating window?

Yes, quite well. Women in both groups followed their window about 6 out of 7 days each week.

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
• Alternate-Day Fasting Improved Premenstrual Mood and Quality of Life in Overweight Women
• Intermittent Fasting Increases Telomere Length in Young Women
• Early Time-Restricted Eating Beats Later Eating for Fat Loss Without Costing Muscle

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