6 Intermittent Fasting Complaints —and How to Solve Them
Intermittent fasting (IF) has a loyal following, but it’s not always smooth sailing. If you’ve ever thought about trying IF—or tried it and hit a few snags—you’re not alone. Here’s a breakdown of the most common intermittent fasting complaints and how to handle them.
Always Hungry? Here’s Why—and How to Calm It
Hunger tops the list of intermittent fasting complaints, especially in the first week or two. Your body is adjusting to a new rhythm, and your hunger hormones—ghrelin and leptin—are figuring out the schedule. I explain more about ghrelin and hunger rhythms here.
Tip: Hydrate often and keep busy during fasting hours. Teas, sparkling water (or Humms!), or a short walk can help distract you while you’re waiting for the ghrelin spike to pass. Over time, hunger becomes more predictable and not so nagging.
Why Some People Feel Sick at First
It’s not unusual to feel a little off when you first start fasting. You can experience headaches, nausea, lightheadedness or dizziness (I’ve written more about how this showed up for me here)—even a little muscle weakness. Most of the time, it’s just your body adjusting to a new fuel schedule. Drops in blood sugar, dehydration, too much caffeine on an empty stomach, or even an electrolyte imbalance can all play a role as well. The good news is that these symptoms usually subside within a week or two as your body adapts.
Tip: Staying hydrated, adding a pinch of salt to your water, and easing gradually into longer fasts can make the transition smoother. I use this salt myself (affiliate link, no extra cost to you).
Tired or Irritable? Your Body Is Adjusting
Some people report fatigue or irritability during fasting periods. This is often a sign that your body is still transitioning to fat as a steady energy source instead of relying only on quick carbs.
Tip: Start with a shorter fasting window (12–14 hours), and break your fast with protein and healthy fats to keep your blood sugar and energy steady and even. Your energy will stabilize as your body adapts.
Struggling to Focus During Fasts? Science Says You’re Not Alone
Mental fog is another common intermittent fasting complaint. This sometimes occurs early on, but research shows it can improve. A review in Nutrition Reviews (Mattson, et al., 2018) found that intermittent fasting can support cognitive function and alertness as your body becomes better at switching between burning carbs and fat for fuel. In addition, another randomized control trial (also by Mattson, et al., 2019) found that in older adults, IF improved memory, executive function, and attention.
Tip: No real tip here; just stick with it, and you’ll eventually reap all those positive outcomes!
Feeling Out of Step Socially? Here’s How to Keep Fasting Without Stress
Skipping breakfast or lunch can feel awkward at brunches or weekend get-togethers. Food is social, and it’s normal to feel self-conscious at first.
Tip: You’ve got a couple of options, depending on the situation.
- When in Rome… join in, eat with your companions, and get back into your fasting rhythm tomorrow.
- Sip on calorie-free drinks, enjoy the company, and break your fast later when you’re ready. People might notice, but chances are they probably won’t care.
- It’s perfectly fine to work in a day or two with breakfast or an early lunch. The point is to make intermittent fasting fit your life, not force your life around it.
- Here, I go over how intermittent fasting can help you get through the holidays with less stress (and cortisol!).
Weight Loss Stalling? Don’t Panic
Many women, especially postmenopausal, are surprised that the scale doesn’t always move quickly. Intermittent fasting can help with fat loss, but hormones, sleep, stress, and activity all play a role. I’ve written more about how sleep affects weight loss in midlife, as well as how stress and cortisol can influence progress.
Tip: Focus on consistency rather than perfection. Sometimes the true wins are internal: steadier energy, improved digestion, better blood sugar control, and fewer late-night cravings. Plus, weight loss naturally slows as we get older, but that doesn’t mean it’s off the table. Stay patient—those pounds can still come off!
Bottom Line: IF Isn’t Perfect—But It’s Worth It
Intermittent fasting is a lifestyle with a rhythm that you get to choose and refine over time; it’s not a magic switch. Most complaints are temporary or situational and can be smoothed out with some adjustments and patience. Once your body adapts, those initial physical disruptions usually go away, and you’ll be glad you stuck it out.
What’s been your experience with IF, and what was (or is) most difficult for you? I’d love to hear, and if it’s something not addressed in this blog, I’ll get back to you personally. Feel free to comment below.
