“Intermittent Fasting”
Have you ever been on a diet at the same time as your male partner and wondered why you are struggling while they drop body fat with ease (insert eye roll here)? That is because men and women are often lumped together when it comes to advice on how to eat and train. But like Dr. Stacy Sims says, “Women are not small men”. We can’t just take the research that is done on men and apply it willy nilly to women expecting the same results. And sadly, that is what a ton of influencers in the health and wellness space are doing these days. One of the suggestions you hear a LOT lately is intermittent fasting. But is it REALLY good for women in midlife? Let’s discuss!
What Is Intermittent Fasting?
Intermittent fasting is the practice of restricting calorie intake to a shortened eating window. Normal eating patterns are usually 3 meals a day and a couple of snacks. With Intermittent fasting, you stop eating for a fasting window and only drink water or noncaloric liquids (like herbal teas). If you think about it, most of us fast between dinner and breakfast if we don’t snack after we eat dinner (in fact, that is why it is called BREAK FAST), but when you intentionally hold off on eating in time window beyond that it would be considered intermittent fasting. An example would be you stop eating at dinner (say, 7:00PM) and then don’t eat until 11AM the next day, you would be fasting for 16 hours.
What does the research say?
Apparently, research shows that it just isn’t that great for most of us gals, especially those of us in midlife. But don’t get me wrong – research shows tremendous benefits from fasting – things like increased autophagy (our bodies process of cleaning up cellular debris), improved insulin sensitivity, lowered LDL and triglyceride levels, and lower levels of oxidative stress (protection from free radical damage). “But Steph, that’s GREAT!” you might be saying. Well, it IS! But the research only shows those benefits for MEN. WHOMP WHOOOOOMMMMP.
“Women are not small men”
Dr. Stacy Sims
Intermittent fasting research done with women show the following:
- NO benefit to insulin sensitivity in sedentary women from the calorie restriction – in fact, women who had high blood sugar saw a worsening in both insulin sensitivity and blood sugar from the fasting
- NO shift in LDL or triglyceride levels
- Minimal, if any, improvement in autophagy
- Increased oxidative stress
- Adverse effects on their endocrine system – thyroid function slowed down
- All of the above effects were amplified in women who exercise
Quick side note here from me: You know what ACTUALLY improves all of the things mentioned above? Exercise. Yup, exercise. In a “goldilocks” amount, using the methodology I mentioned in part 1 of this series.
Intermitting Fasting – Stress
In midlife, especially during perimenopause through post-menopause, our hormone levels change. Cortisol levels rise, making us have more SYMPATHETIC drive. The sympathetic branch of the nervous system is associated with “fight or flight” whereas the PARASYMPATHETIC branch is associated with “rest and digest”. Intermittent fasting elevates cortisol, signaling our bodies to hold onto body fat and turn down our resting metabolic rate. YIKES!
In addition to elevated cortisol, there are other hormonal issues at play during this time. When our brain perceives that we’re not getting enough nutrition, we have a reduction in the production of a neuropeptide called kisspeptin (love that word!) which is responsible for our sex hormone, endocrine and reproductive function (it turns it on or off). Kisspeptin plays a big role in maintaining healthy glucose levels, appetite regulation, and body composition. When we fast or drop our calories too low, our kisspeptin level drops and can throw off our whole hormonal balance. This also impacts our thyroid function, turning down our resting metabolic rate. You can start feeling tired and fatigued.
So, let’s recap here. In midlife, we already have changes in our sex hormones, including elevated cortisol levels. Not eating elevates our cortisol levels AND perturbs our kisspeptin levels, sending us in an additional state of hormonal whack.
Resources
If you want to learn more about intermittent fasting in midlife, I highly recommend reading or watching the following:
Great article on Intermittent Fasting from Precision Nutrition Intermittent Fasting for Women: Everything You Need to Know (precisionnutrition.com)
Learn about why fasted training is not great for women:
Learn more about why weight loss feels so difficult in midlife:
