Nutrition should not be approached the same way for both males and females. Yes, there is a lot of overlap, but in order to truly optimize nutrition, females should take into consideration how hormonal fluctuations have an effect on everything from hunger, to strength levels, to fat oxidation.
Reproductive Hormones and Menstrual Cycle
The female menstrual cycle lasts for approximately 28 days. This time can be broken down into 3 distinct parts: the follicular phase, ovulation, and the luteal phase. The follicular phase occurs approximately from day 1 (first day of period– full bleeding, not spotting) to day 14 of a woman’s cycle. Day 14 is when ovulation occurs, and then the luteal phase follows from day 14 to day 28, when menstruation begins again.
During the follicular phase, the predominating hormone is estrogen, whereas during the luteal phase, the predominating hormone is progesterone. The fluctuations in estrogen and progesterone both have a substantial effect on hunger, cravings, metabolism, energy levels, strength, power output, and substrate utilization.
Optimizing Your Diet Around Your Cycle
Hunger: Hunger typically elevates around the 3rd-4th of a woman’s cycle (right before starting your period) and peaks right before menstruation starts. This is because estrogen acts to counteract hunger, and progesterone has been shown to increase hunger. Additionally, metabolism is typically increased during this time, which leads to increased hunger levels.
Cravings: Cravings typically increase around the same time as hunger, but are more likely to peak during menstruation rather than before.
Basal Metabolic Rate: Metabolism has been shown to increase after ovulation (day 14), during the luteal phase (after ovulation, but before menses begins again). Metabolism is decreased during the follicular phase (first day of period until ovulation).
Substrate Utilization: Research shows that carbohydrate utilization is higher during the follicular phase (day 1-14) and fat utilization is higher during the luteal phase (day 14-28).
Diet Recommendations
- Week 1*: Cravings are typically highest during this time, but metabolism and fat utilization are lower. Since carb utilization is higher, carb intake can be increased, which may help reduce cravings as well.
Recommendation: Moderately increase carbohydrate consumption (from 5% of total calories to ~10% based on your needs), moderately reduce fat consumption, reduce total caloric intake
- Week 2: Metabolism and fat utilization are still lower than during the luteal phase, but cravings should start to normalize.
Recommendation: Follow a similar protocol as week 1, but consider increasing fat closer to normal and dropping carbohydrate back if blood ketone levels decrease
- Week 3: Fat utilization and metabolism have both increased, while carbohydrate utilization has decreased.
Recommendation: Reduce carbohydrate intake back to 5% of total daily calories (or less), increase fat intake to normal.
- Week 4: This week is similar to week 4 with fat being the primary fuel source and metabolism being increased, but hunger and cravings tend to begin during this time. Increasing protein during this time will help meet total daily calorie needs (from increased BMR) and reduce hunger and cravings.
Recommendation: Maintain a lower carbohydrate and high fat intake but, also, increase protein intake.
*week 1 begins with the first day of menses
Optimizing Your Training Around Your Cycle
Strength: Research suggests that strength levels typically increase during the follicular phase and decrease after ovulation (during the luteal phase).
Energy: Energy levels tend to decrease after ovulation, plateau before menses, and increase towards the end of menses into week 2.
Training Recommendations
- Week 1*: Focus on strength-based workouts (higher weight, lower rep range)
- Week 2: Focus on hypertrophy (moderate weight, 8-12 rep range)
- Week 3: Focus on hypertrophy or endurance (moderate weight. 8-12 rep range, or lower higher, higher rep range 12+)
- Week 4: Focus on low-intensity activities or deloading
Deloading: Reduce both the weight and the rep range
Low-Intensity Recovery Activity Examples:
- Walking/hiking
- Yoga
- Swimming
*week 1 begins with the first day of menses
Menopause
During and leading up to menopause, estrogen levels significantly decrease. Since estrogen works in a negative feedback loop with FSH (follicular stimulating hormone), FSH remains high, while estrogen stays low. This can cause weight gain from increased hunger, increased cravings, decreased metabolism, and fatigue. Increasing fat intake may help regulate hormone production.