The Hidden Pitfalls of Intermittent Fasting

If you’ve been hearing about intermittent fasting (IF) and wondering if it would help you optimize your health and weight, a new study shows that IF does not help with weight loss — and, in fact, can cause you to lose lean muscle!

Let’s take a look at what this new study found, and what REALLY works for women instead.

Potential Pitfalls of Intermittent Fasting

The new study looked at the hidden pitfalls of time-restricted eating, which is a form of intermittent fasting (IF). Intermittent fasting is an approach to eating that has been widely recommended for people in recent years as a way to balance blood sugar, lose weight and maintain a healthy weight, and guard against chronic diseases like diabetes and cancer. It’s one of several popular eating strategies that are widely recommended by (mostly male) biohackers.

The research found that participants (both men and women) who practiced time-restricted eating  for 12 weeks didn’t lose significantly more weight than the control group, but the weight they did lose was primarily lean muscle mass, not fat. The same was not true for the control group. What’s more, the researchers didn’t observe any significant differences in fasting glucose, fasting insulin, HOMA-IR, and total cholesterol between the two groups. 

Participants in the time-restricted eating group ate freely between the hours of noon and 8:00pm, skipping breakfast and late-night snacking. The control group ate normally without time restrictions. The findings of this study match up with previous research that suggests skipping breakfast is a bad idea when weight loss is the goal. In fact, research suggests that a good breakfast filled high-quality protein, healthy fats and complex carbs can help balance hormones, boost fertility, and ease period problems. Breakfast is a key part of the FLO Protocol. 

This study backs up what I’ve been saying for a long time: Intermittent fasting, and other fad diets, are not ideal for women in their reproductive years. 

It is also worth noting that historically women in their pre-menopausal years are left out of medical, fitness, and nutrition research, but results from these studies that exclude them are shared in a way that encourages them to try each new diet or fitness plan. When women try these approaches and don’t get the promised results, they get discouraged or assume they did something wrong. In fact, it can be argued this exclusion is a root cause of the unnecessary symptoms women face hormonally.

What IS the Best Diet for Women? 

The best eating strategy for women in their reproductive years is one that supports the infradian rhythm, or the unique 28-day cycle that every menstruating woman experiences. 

I always recommend a healthy, hearty breakfast for women, one that will stabilize blood sugar all day long. But breakfast is just one component of eating in sync with the infradian rhythm. 

Because our unique female biochemistry is cyclical in nature, we benefit the most when we eat in a cyclical pattern, one that aligns with our innate 28-day hormone cycle. Eating for hormonal health requires shifting what we eat each week to support our body’s shifting needs. 

Your body isn’t the same every day and your diet shouldn’t be either! I created The Cycle Syncing Method™ method to give women an easy, intuitive way to match their food, exercise, and lifestyle choices with their infradian rhythm. 

Practicing The Cycle Syncing Method™ is easy. Start by getting familiar with your 28-day hormone cycle. How do you do that, you ask? The best place to start is with the MyFlo app. It lets you track your cycle and deepen your knowledge of your infradian rhythm. The next step is to tailor your food, movement, supplements, and lifestyle choices to your unique strengths, weaknesses, and needs during each phase of your cycle.

You already know on some level that your body needs different things at different times. Do you have certain cravings during different weeks of the month? Do you feel hungrier at different stages of your cycle? This is your infradian rhythm! Practicing The Cycle Synching Method™ with food starts by choosing specific foods that will support optimal hormone balance in each phase.

The Cycle Syncing Method™: How to Get Started

At Flo Living, we teach women how to get in sync with their cycle and eat to support their infradian rhythm with food. In today’s post, I’m going to give you the first critical steps in practicing The Cycle Syncing Method™ with food and some specific foods to eat during each phase of your cycle. 

Here are some of the high-level things to keep in mind when you start eating in line with your cycle:

1 - Modulate caloric intake based on the infradian rhythmic effect on your metabolic rate. In an article published in the International Journal of Obesity, researchers found that a woman’s capacity to burn calories changes over the course of the monthly hormone cycle. Specifically, in the first phase of your cycle, metabolism is slower. In the second half of your cycle, metabolism revs up and women burn anywhere from 89 to 279 extra calories per day. (Food cravings tend to increase in the second half of the cycle, too, as the body prepares for a pregnancy.) Eating strategies like IF don’t take these cyclical changes in metabolism into account and, by following them, women can end up adding weight.

2 - Choose foods that help with hormone creation and breakdown in each relevant phase of the cycle. Menstruating women need more support during the ovulation peak and the first half of the luteal phase, and we need more support with progesterone production in the luteal phase. And we need more amino acids in the menstrual phase to build more hormones for the next part of the cycle to begin again.

3 - Change workout intensity based on the infradian effect on metabolism and resting cortisol levels. In the first phase of the hormone cycle, for example, menstruating women have an easier time burning fat and gaining lean muscle because of their hormone profile during that time. That makes the first half of the cycle the best time for high-intensity workouts, according to research published in PLOS ONE. But high intensity training may do more harm than good during the second half of the cycle. Research shows that intense exercise during the second phase of the cycle may lead to irregular and missed periods and the potential to store fat rather than lose it. 

4 - Strategically plan projects based on the infadian rhythmic effect on brain chemistry - which changes up to 25% over the month and creates different cognitive advantages, like dialed in verbal skills or super focus and concentration. Work smarter!

Some other great strategies

#1 Choose low-glycemic whole foods that help balance blood sugar. Balanced blood sugar is part of why eating a big breakfast matters so much. If you don’t eat in the morning — or if you eat something high in sugar (and especially if you have caffeine before you eat) — your blood sugar will be on a roller coaster all day and that is bad news for your hormones. To keep your blood sugar stable throughout the day, focus on eating healthy fats, high-quality proteins, and complex carbohydrates, and avoiding simple carbs and processed sugars as much as possible. 

Lunch should be the biggest meal of the day and make sure to include some complex carbs (like quinoa) and good fats (like the kind of fat found in avocado). If you crave sugar in the afternoon, reach for sweeteners that don’t spike blood sugar as dramatically as refined sugar. I like honey and coconut nectar. Be careful to avoid hidden sugars in pre-packaged foods like bread and pasta sauces. 

#2 Ditch caffeine. Caffeine interferes with hormone balance in several key ways, but today I’m going to focus on how caffeine contributes to cortisol dysregulation. A healthy adrenal response is essential for balanced hormones and better periods, and caffeine taxes the adrenal glands and sends cortisol off course… which throws your hormones out of balance (among other things). Reduce or ditch coffee or caffeinated tea, and be mindful of how much dark chocolate you eat! There is nothing wrong (and a lot right!) with eating some dark chocolate now and then, but it contains caffeine just like coffee, so mindfulness is key. 

#3 Incorporate foods that help the body eliminate estrogen. Estrogen dominance is one of the most common hormone imbalances that menstruating women experience. The liver helps flush excess estrogen from the body, and specific foods help support the liver in the process of detoxification, including broccoli, broccoli sprouts, cauliflower and Brussels sprouts, and any other cruciferous vegetable. You can also take a supplement that supports liver detox. 

Foods for Each Phase of the Cycle

I do a deep dive on specific foods to eat in each phase in my new book In the Flo, and what to eat and when to eat it is part of all our courses, programs, coaching and classes at Flo Living, but I want you to be able to get started practicing The Cycle Syncing Method™ today. Here is a brief intro on how to eat in sync with your cycle:

Follicular phase

• Focus: Boosting estrogen, getting the body ready for ovulation
• Key Foods: Whole foods that contain plant compounds that mimic estrogen
• Example Food: Flax seeds

Ovulatory phase

• Focus: Supporting estrogen elimination
• Key Foods: High-fiber whole foods
• Example Food: leafy greens

Luteal phase

• Focus: Boosting progesterone
• Key Foods: Vegetables high in B vitamins
• Example Food: sweet potatoes, chickpeas

Menstrual phase

• Focus: Stable mood and energy
• Key Foods: Healthy protein sources
• Example Food: beef

At FloLiving, we dream of a future in which women in their reproductive years partner with their gynecologists AND with our team to get best-in-class hormonal health care. With the right support, women in their reproductive years can ease their symptoms, live with less pain, and look and feel their best — which is what every woman deserves.

NOTE: We use the words “woman” and “women” and she/her pronouns throughout these posts for ease of writing, but the principles and advice apply to any person, regardless of gender identity, who was born with female physiology. At the same time, if you are a person born with male physiology and you identify as non-binary or you are transitioning to identify as female, using a cyclical support system can help you feel more in sync with your female energy.