Despite a few benefits found in research, it's important to consider the context and remember that it's not appropriate for all people at all times. Women of reproductive age need to be particularly careful with intermittent fasting as their bodies are more sensitive to stressors like prolonged fasting and caloric restriction.

Intermittent fasting itself is a stressor on the body, and in the context of our modern-day life that's ALREADY filled with chronic emotional, physiological and environmental stressors… (you know I'm right) intermittent fasting might do more harm than good.

Fasting increases cortisol which can lead to blood sugar dysregulation, increased insulin resistance, lean muscle loss, fatigue AND disruptions to thyroid function over time. In the short-term, fasting may lower thyroid stimulating hormone, but elevated cortisol on a persistent basis can reduce the conversion of thyroid hormone. You with me?

 Fasting can also lead to consistent undereating (which we see A LOT) and we know negatively influences female hormones in mannyyyyy ways. The caloric restriction caused by intermittent fasting could lead to loss of the menstrual cycle and interfere with fertility.

 For ya'll who aren't concerned about fertility at this point in your life (me!) fasting can also increase hunger and obsession with food, leading to overeating or a cycle of restricting and bingeing. Fasting can be detrimental for women with eating disorders or chronic dieters who have a history of restricting foods or disordered eating. It's just not the right way to go about things. 

 When the body goes for prolonged periods without food…hunger hormones are released that increase appetite. We OFTEN see women applying intermittent fasting incorrectly by skipping breakfast everyday and eating late into the evening (or taking days off of fasting and going balls to the walls - eating ALL OUT) which we know can disrupt circadian rhythms and contribute to hormone imbalance - ya'll. 

We also talk to new clients practicing intermittent fasting who are completely ignoring their body's biological hunger cues altogether which is not health-promoting, physically or mentally.

How to Safely Intermittently Fast?

Here is me reiterating that fasting is not beneficial—or safe—for everyone. We do not recommend IF to women who aren't sleeping enough, don't eat enough or don't eat consistently, have irregular or absent cycles, experience thyroid issues, have a history of current or past disordered eating, are under a lot of stress or have blood sugar issues. 

I'm an advocate for eating consistently which is a really supportive way to reduce stress on the body and balance blood sugar. 

If for some reason you have the go-ahead from your doctor or dietitian to fast, start slow. 

Fasting for just 12 to 14 hours overnight can have metabolic benefits. You don't necessarily have to fast for 16 or 18 hours to experience the benefits. If fasting helps you with evening snacking, then aim to not eat from 8pm - 8am (which is a pretty normal schedule anyway). 

First, count how many hours you currently go from when you stop eating at night to when you start eating the next day. Consider extending your fast by one hour to start, then increase by two hours, etc.  We still recommend eating three balanced meals with protein, high-fiber carbohydrates and healthy fats, spaced evenly throughout the “eating window”.

Those who have never been big breakfast eaters may find it easy to avoid eating until 10 or 11 am, while others are hungry when they wake up. The most important thing is to listen to your body and if you're hungry, eat. Women who work out regularly may find it difficult to stick to intermittent fasting. And if it's that time of the month and you're ravenous, it will also be hard to fast.

You may be wondering Ashley: Does coffee break the fast? If there's anything in it, then technically, yes. Black coffee has zero calories. But consider your goals—are you doing this for weight loss? If so, remember that IF doesn't lead to any more weight loss than a calorie deficit overall, so you are probably fine to add a little creamer to your coffee. Are you doing it for blood sugar control? If so, then spiking your sugar with a flavored latte is not the best way to start the day.