The short answer: Probably yes, but only a little. A 2020 meta-analysis of 26 studies found a small rise in resting metabolic rate in the luteal phase, the stretch between ovulation and your period. A 2026 systematic review put the rise at about 30 to 120 kcal per day, or roughly 3 to 5%. A separate meta-analysis of energy intake found women ate about 168 kcal per day more in the same phase. The extra burn does not create room for extra food.

What happens to your metabolism before your period?

The week before a period falls in the luteal phase. This phase starts at ovulation and ends when bleeding starts. The Office on Women's Health says a normal cycle lasts 24 to 38 days. It also says the time from ovulation to the next period ranges from 7 days to 19 days.

Researchers compare this phase with the follicular phase, which runs from the first day of a period to ovulation. Most studies measure resting metabolic rate (RMR) once in each phase. RMR is the energy your body uses at rest. Our guide on how to calculate TDEE shows where RMR fits in your daily total.

Researchers have long suspected that progesterone drives the change. The author of a 1986 calorimetry study named progesterone from the corpus luteum as the likely cause. The evidence for the mechanism is weaker than the evidence for the rise itself.

How many extra calories do you burn in the luteal phase?

The measured numbers shrink as the studies get newer and larger.

  • 1986, whole-body calorimetry. Ten women were measured for 36 and 46 hours at a time. Eight of the 10 showed a rise of 8 to 16% in 24-hour energy expenditure during the luteal phase. The author reported a 9% increase overall.
  • 1989, metabolic ward. Eight women ate a constant diet for one full cycle. Sleeping metabolic rate was 6.1% higher in the late luteal phase than in the late follicular phase. The rise in 24-hour energy expenditure was not statistically significant.
  • 1992, respiratory chamber. In an NIH study of 121 women and 114 men, women in the luteal phase burned 106 kcal per day more than women in the follicular phase. That figure compares different women. It does not follow the same woman across her cycle.
  • 2024, indirect calorimetry. A study of 20 women measured RMR at 5,042 kJ per day in the follicular phase and 5,197 kJ per day in the luteal phase. The gap is 155 kJ per day, which converts to about 37 kcal.
  • 2024, the largest recent sample. A Finnish study of 38 women found luteal resting energy expenditure 40 kcal per day higher. The 95% confidence interval ran from -2 to 82 kcal per day, so the result was not statistically significant. With four outliers removed, the difference was 44 kcal per day and significant.

The two 2024 measurements are both near 40 kcal per day. That is at the low end of the 30 to 120 kcal range in the 2026 review.

How consistent are the studies?

Not very. The 2020 meta-analysis pooled 26 studies with 318 women in total. It found a small but significant effect toward higher RMR in the luteal phase (effect size 0.33). The authors then looked only at studies published since 2000. The effect dropped to 0.23 and was no longer statistically significant (p = 0.055).

The authors listed the reasons for caution. Sample sizes were small. Studies carried a risk of bias in how they measured both cycle phase and RMR. They did not report control of confounders.

The 2026 review covered seven studies published from January 2020 to September 2025. Five reported a trend toward a higher metabolic rate in the luteal phase, and four of those reached statistical significance. The reviewers said the shift may overlap with normal day-to-day variation or measurement error.

Some well-controlled studies find nothing. A study of rugby league athletes confirmed cycle phase with blood hormone tests and an ovulation test. It found no effect of cycle phase on RMR in 11 naturally cycling athletes.

Individual response also varies. In the 1986 study, two of the 10 women did not show the rise.

Do you eat more before your period?

On average, yes. A 2025 meta-analysis in Nutrition Reviews pooled 15 datasets with 330 women. Energy intake was higher in the luteal phase than in the follicular phase. The crude average difference was 168 kcal per day. The authors noted repeated inconsistencies in how studies measured intake and defined cycle phase.

Cravings are part of the picture. The Office on Women's Health lists appetite changes or food cravings among the symptoms of premenstrual syndrome. It says more than 90% of women report some premenstrual symptoms.

Smaller studies point in the same direction:

Compare the two averages. Intake rose about 168 kcal per day. Recent RMR measurements rose about 40 kcal per day. These numbers come from different studies and different women, so they do not subtract cleanly. The direction is still clear: appetite tends to rise more than expenditure does.

Does hormonal birth control change the pattern?

The limited evidence suggests the rise does not appear in pill users. The Finnish study included 19 women on monophasic combined oral contraceptives. Their resting energy expenditure differed by -2 kcal per day between the active and inactive pill phases. The confidence interval was wide, from -82 to 79 kcal per day.

The 1986 study has one early data point. One woman showed a 14% rise after ovulation in a natural cycle. She showed no significant change during a month on an oral contraceptive. One person is not proof.

The rugby league study compared 11 naturally cycling athletes with 12 hormonal contraceptive users. Seven used a progestin implant, four used a combined pill, and one used an injection. Contraceptive use had no significant effect on RMR.

These studies are small. They do not cover every contraceptive type in enough numbers to give separate answers for each.

Should you change your calorie target before your period?

The evidence does not support a higher target. A rise of about 40 kcal per day is small. Food logs carry their own error, which our article on how accurate calorie counts are covers. No study here measured your personal change, and some women show none.

Some practical points follow from the data:

  • Expect more hunger. Higher intake in the luteal phase is a measured average, not a personal failure. Plan for it instead of adding calories to match a burn that may not exist for you.
  • Read the scale with care. In the metabolic ward study, body weight varied across the cycle on a constant diet. Our article on why the scale jumps overnight covers water weight.
  • Compare like with like. The 2020 meta-analysis advised researchers to test RMR in the same cycle phase each time. The same logic applies to your weight trend. Compare one cycle week with the same week of the next cycle.

Thyroid hormones also affect metabolic rate. The 1989 study found no significant changes in thyroid hormone levels that explained the luteal rise. Our sibling site thyroid.md covers thyroid conditions.

The bottom line

You may burn slightly more calories in the week before your period. Recent studies measure the rise at about 40 kcal per day at rest, and a 2026 review gives a range of 30 to 120 kcal per day. The finding is not consistent: the pooled effect in studies since 2000 was not statistically significant. Energy intake rises by a larger average amount, about 168 kcal per day. Women on combined oral contraceptives showed no phase difference in one study. Keep your calorie target steady and expect more hunger and a less steady scale.

Last updated: October 2026. This article is for informational purposes only and does not constitute medical advice. Talk with your doctor if premenstrual symptoms, appetite changes or cycle changes disrupt your daily life.