A first-person account of two years of intermittent fasting that led to weight loss but also fatigue, brain fog, and menstrual disruption — plus what changed after reintroducing breakfast.
Intermittent fasting (16:8) can produce weight loss but may trigger chronic stress responses when combined with fasted intense exercise.
Women’s reproductive hormones and menstrual cycles are sensitive to chronic fasting-related stress via the HPA axis, which can suppress reproductive signaling.
If you experience fatigue, mood changes, brain fog, or missed periods while fasting, consider re-evaluating meal timing and discuss it with your clinician.
# The experiment I spent about two years doing intermittent fasting, mainly a 16:8 schedule: skipping breakfast, drinking black coffee, and squeezing my eating into an eight-hour window. I trained fasted most mornings — heavy lifts and cardio at 6:30 a.m. — then ate my first meal around 11 a.m. The routine saved time, felt simple in a busy season, and produced visible changes in body composition.
# The unexpected costs Weight loss and convenience were real. But so were downsides I didn't recognize at first: chronic fatigue, brain fog, low motivation for workouts, irritability, and eventually menstrual irregularities. Over time I found myself exhausted, going to bed earlier than I used to, and skipping periods. What felt like a fitness hack had become a stressor my body was reacting to.
# Why this can be different for women
# How my routine changed and why The turning point was another missed period and a frank conversation with my doctor. I started eating breakfast within 30 minutes of waking. It felt strange at first after two years of skipping the morning meal, but within weeks I noticed improved energy, clearer thinking, and more motivation to train. Breakfast became a predictable source of fuel rather than something to avoid.
# Practical takeaways for readers
# Bottom line Intermittent fasting produced visible benefits for me, but it also produced physiological consequences I initially ignored. Reintroducing breakfast restored energy and helped normalize my routine. If you're experimenting with fasting, pay attention to how your body signals stress and consult a clinician if reproductive or sustained health changes occur.
For decades, skipping breakfast was treated almost like a nutritional crime—but science hasn’t produced a universal rule that everyone needs to eat the moment they wake up. Serena Williams recently drew attention to the question when she described her training-day eating routine and said she isn’t much of a breakfast p
Pushing your first meal of the day into the afternoon might do more than make your stomach growl; it could significantly raise your risk of dying early. Do you regularly roll out of bed, chug black coffee, and ignore food until lunchtime? According to data from the Centers for Disease Control and Prevention, roughly 15
Decades of nutrition advice may have gotten breakfast wrong. Here’s what researchers actually want you to know about the first meal of the day.
We all know mornings can be hectic with kids and sometimes that means they might skip breakfast before school. But that habit could hurt them in the long run.
Fasting around your workouts doesn’t necessarily mean sacrificing strength or endurance.
Fasting around your workouts doesn’t necessarily mean sacrificing strength or endurance.
Loading more related stories...
Open the app view to save this story, compare related coverage, and continue from the same source.