The menstrual cycle also affects our sensitivity to the insulin hormone and, in turn, our insulin resistance. In the beginning half of the cycle, we are more sensitive to the effects of insulin and therefore able to take up glucose into the cells more effectively. This means that in the follicular phase, before ovulation, women are better able to efficiently metabolize carbohydrates for energy. One reason for this is that estrogen increases insulin sensitivity. If you are going to eat carbohydrates, the ideal time to do so is in the first phase of your menstrual cycle. As progesterone levels rise and estrogen dips in the second phase of the cycle, we lose this sensitivity and become more insulin resistant. Insulin resistance impairs our ability to properly metabolize carbohydrates for energy, thereby increasing blood sugar, insulin levels, and fat storage during this time when a high-carbohydrate diet is consumed. Choosing low-carb foods is an effective way to bypass the impaired glucose uptake. Arguably one of the biggest benefits of a ketogenic diet is the alternative metabolic pathway to combat a faulty insulin response. Eating a keto diet during times of insulin resistance can help alleviate the effects of insulin resistance, balancing blood sugar and hormones. You can start keto whatever time suits you best, but consider starting your diet during the follicular phase of your cycle. After your menstrual bleed has ended and your estrogen is rising, you may have better compliance with your new dietary choices. That’s right: Impulsiveness can be affected by which part of the menstrual cycle you are in. Rising levels of estrogen in the follicular phase are related to decreased impulsive behavior compared to stages of the cycle when estrogen is low. As estrogen levels fall in the second phase of the cycle, impulsive behavior rises. This time also coincides with increased food cravings, which can further provoke impulsive eating behavior. Even with the best intentions, the combination of increased appetite, intense cravings, and impulsiveness can lead to excess intake and crush our efforts to even get started on a diet. Beginning your diet when estrogen levels are at their peak in the follicular phase of your cycle may help you battle the urge to quit your diet before you even get started. Another reason you could be experiencing erratic periods has to do with fat loss and the release of stored hormones and toxins. Adipose tissue is not just a storage space for fat—all kinds of things are stored here! They include fat-soluble vitamins, hormones, pollutants, toxins, and a variety of other substances that are foreign to the body. While stored, they are slowly released into the bloodstream, but they are rapidly freed during weight loss as the fat deposits are burned for energy. As these extra components enter the blood, your hormones and menstrual cycle may be affected. As we know, hormone balance is a delicate process, and even slight increases can trigger deviations in the system. Your body will either metabolize and excrete the excess that’s been released or reabsorb it, so any imbalance this causes is only temporary. Ultimately you will be better off, as the pollutants in your body tend to decrease by about 15 percent after weight loss. This also supports the argument for a slow and steady approach to fat loss, as you don’t want to load your liver with an overabundance of toxins to metabolize all at once. Finally, a drop in carbohydrates has the potential to affect thyroid hormone production. For those susceptible to impaired thyroid function, this could also affect your menstrual cycle. A dramatic drop in carbohydrates can undoubtedly affect your menstrual cycle, specifically if you are at risk of or have a thyroid-related disease. Beginning a keto diet doesn’t have to be all or nothing; you don’t have to go from high carb to no carb in the blink of an eye. Gradually ease into carbohydrate restriction if cutting carbohydrates quickly is problematic. You can also eat carbs strategically to counterbalance this effect. Listen to the clues your body gives you and adjust your approach accordingly.
