Many women report that their appetite and food cravings change throughout their menstrual cycle, but a new study suggests this might not actually happen as much as we think. Researchers tracked 18 healthy young women during two different phases of their cycle—once when hormone levels were lower and once when they were higher. They measured how much the women ate in a lab setting and at home, checked their appetite levels, and tested their metabolism. Surprisingly, the women ate about the same amount of food and reported similar hunger levels in both cycle phases, even though their metabolism showed a slight tendency to increase during the second half of the cycle. This challenges the common belief that the menstrual cycle significantly affects eating habits.

The Quick Take

  • What they studied: Whether women eat different amounts of food and feel different levels of hunger during different phases of their menstrual cycle
  • Who participated: 18 healthy young women (average age 21 years) with regular menstrual cycles who were not taking hormonal birth control
  • Key finding: Women ate roughly the same amount of food and reported similar hunger levels during both the early and late phases of their menstrual cycle, both in a controlled lab setting and in their normal daily lives
  • What it means for you: If you’ve blamed your menstrual cycle for changes in your eating habits, this research suggests the cycle itself may play a smaller role than you thought. However, this was a small study, so individual experiences may vary—some women may still notice real changes in their appetite during their cycle

The Research Details

This study followed 18 women and tested them twice: once during the early part of their menstrual cycle (when certain hormones are lower) and once during the later part (when hormones are higher). The researchers confirmed which cycle phase each woman was in by checking hormone levels in her urine. Before each test visit, women ate the same balanced diet for two days to make sure their starting point was identical. During the lab visit, researchers measured how fast the women’s bodies burned calories at rest, asked them to rate their hunger before and after eating a standard breakfast, and let them eat as much as they wanted from a lunch meal while researchers weighed the food. The women also tracked their appetite and food intake for 2.5 days at home after each visit.

Previous research relied mainly on women remembering and reporting what they ate, which can be unreliable. This study used more objective methods—actually weighing food and measuring metabolism—which gives us a clearer picture. Testing women in both a controlled lab and their normal home environment helps show whether any differences are real or just happen in one setting.

This study has several strengths: it used objective measurements (weighing food, measuring metabolism) rather than just asking women to remember what they ate, it tested women in both controlled and real-life settings, and it confirmed cycle phases using hormone testing. However, the sample size was small (only 18 women), all participants were young and healthy with normal weight, and the study only looked at two specific points in the cycle. Results may not apply to all women, especially those with irregular cycles, different ages, or different body types.

What the Results Show

When researchers looked at how much women ate during the lab lunch meal, there were no meaningful differences between the early and late cycle phases. Women ate approximately the same amount of food and the same amounts of protein, carbohydrates, and fat in both phases. Similarly, when women tracked their eating at home for 2.5 days, there were no significant differences in total food intake or nutrient intake between the two cycle phases. Hunger ratings before and after breakfast were also similar in both phases. Food cravings, measured using a standard questionnaire, did not differ between cycle phases. These findings held true whether researchers looked at the data overall or compared specific time points.

The one result that came close to showing a difference was resting metabolic rate (the number of calories your body burns at rest). During the later cycle phase, women’s metabolism tended to be about 104 calories per day higher, but this difference was not quite statistically significant (P = 0.074). This means it could be a real effect or could have happened by chance. If real, this small increase in metabolism might be why some women feel slightly warmer or more energetic during the later part of their cycle, but it didn’t translate into changes in eating behavior.

Many previous studies found that women reported eating more or craving certain foods during the later part of their menstrual cycle. However, those studies relied on women’s memories and self-reports, which can be influenced by expectations and beliefs about the menstrual cycle. This study’s use of objective measurements (weighing actual food eaten) suggests that the reported differences in previous research may not reflect actual changes in eating behavior. The findings align with a growing body of research questioning whether the menstrual cycle has as large an effect on eating as commonly believed.

The study included only 18 women, all of whom were young (average age 21), healthy, and had normal body weight. Results may not apply to older women, women with irregular cycles, women with eating disorders, or women with different body compositions. The study only examined two specific points in the menstrual cycle and didn’t look at other phases. The study period was relatively short (2.5 days of home monitoring), so longer-term patterns weren’t captured. Additionally, all participants knew they were being studied, which might have changed their eating behavior.

The Bottom Line

Based on this research, you should not assume that your menstrual cycle is the main driver of changes in your appetite or eating habits. If you notice changes in hunger or cravings during your cycle, other factors (stress, sleep, activity level, food availability) may be more important. However, this is just one small study, so if you personally experience strong appetite changes during your cycle, that’s still valid and worth paying attention to. Consider tracking other factors alongside your cycle to identify what actually affects your eating. (Confidence level: Moderate—this is a small study with limited participants)

This research is most relevant to healthy women of reproductive age who wonder whether their menstrual cycle affects their eating. It’s particularly useful for women who feel frustrated by appetite changes they attribute to their cycle. This study does NOT apply to women taking hormonal birth control (which changes natural hormone patterns), women with irregular cycles, or women with a history of eating disorders. If you have concerns about significant appetite or weight changes related to your cycle, talk with your doctor.

If you decide to track your eating and appetite in relation to your cycle, give it at least 2-3 months to see patterns. Individual responses vary, and it may take several cycles to identify whether changes are real or coincidental.

Want to Apply This Research?

  • Log your daily food intake (total calories or meals) and rate your hunger level (1-10 scale) each day for at least 3 menstrual cycles. Also track your cycle phase (early or late) and note other factors like sleep quality, stress level, and exercise. This will help you identify whether your cycle or other factors drive changes in your eating.
  • Instead of assuming your cycle controls your appetite, use the app to identify your actual eating patterns. If you notice changes, investigate other causes first: Did you sleep poorly? Are you stressed? Did your exercise routine change? This shifts focus from blaming your cycle to understanding your real triggers.
  • Create a dashboard that shows your food intake and hunger ratings side-by-side with your cycle phase, sleep, stress, and activity levels. After 3 months, review the data to see which factors actually correlate with changes in your eating. This personalized data is more useful than general research findings.

This research suggests that menstrual cycle phase may not significantly affect eating behavior in healthy young women, but individual experiences vary. This study involved only 18 participants and may not apply to all women. If you experience significant changes in appetite, cravings, or eating patterns related to your menstrual cycle, or if these changes concern you, consult with a healthcare provider or registered dietitian. This information is not a substitute for professional medical advice. Women with a history of eating disorders should discuss cycle-related eating changes with their healthcare team.