When used at the wrong times (or in the wrong individual), intermittent fasting can actually stall weight loss, or even make you GAIN. One of the major flaws with the science behind intermittent fasting (IF) is that most studies have been done on men, not women. Men experience fewer hormonal fluctuations than women do, and what’s appropriate or healthy for women can change depending on what phase of their monthly cycle they’re in. All hormones are connected, so changes in levels of estrogen/ progesterone can affect insulin, cortisol, thyroid, and other hormones related to metabolism and weight. In general, post menopausal women tend to handle intermittent fasting better since they experience less hormonal fluctuations than premenopausal women.
While IF can be useful for certain medical conditions (such as pre diabetes/insulin resistance, neurological decline, and seizure disorders), it can also cause serious metabolic dysfunction in women with low blood sugar tendencies, low thyroid function, adrenal fatigue, and other hormone imbalances. This is especially true when it comes to skipping breakfast. Think about it this way: you’ve been fasting all night long, so when you wake up, your fuel tank is on empty. Trying to push through your morning on empty results in a few things:
- Number 1: Low blood sugar causes an increase in cortisol. Cortisol is a stress and fat storage hormone. If this hormone rises too high, you start breaking down muscle and storing fat
- Number 2: When you start the day without fuel, your brain recognizes this and spends the rest of the day trying to make up for this deficit. It starts signaling for “quick fuel” (aka simple carbs and sugar)
- Number 3: Blood sugar and hormones are like a married couple. If you have too many highs and lows throughout the day (which is exactly what happens when this system is imbalanced), you start
to see imbalances in insulin, DHEA, testosterone, estrogen, and progesterone. Hormone imbalances generally favor weight gain and fat storage.
The more appropriate way for MOST women to reap the benefits of intermittent fasting without destroying their blood sugar and hormones is to practice a 12 hour overnight fast. For example, you’d finish eating dinner by 7 pm and wouldn’t eat again until 7 am the next day. Some women can handle 14-16 hours (meaning earlier dinner and later breakfast), but that’s all bio individual!
As always, work with a qualified practitioner when making major changes to your nutrition plan or lifestyle. Your hormones will thank you.