After last week’s post about why breakfast matters, I knew this question was coming.
“So… are you saying intermittent fasting is bad?”
No.
But I am saying that how and when you fast matters more than the fact that you fast at all. I’ve tried it. . .intermittent fasting, OMAD, TMAD, 48 hour fasting. . . AND until I dialed it in to match my body (our circadian rhythm) it didn’t work. Well, it worked for a bit, but the crash was right there.
You see, most people don’t run into trouble because they fasted. They run into trouble because they fasted against their circadian biology or under-ate prior to fasting, and then wondered why their hair fell out and their face looked tired. I didn’t undereat and my hair didn’t fall out, but I messed up my sleep and stressed out my adrenals.
Let’s clean this up so you can go into it with a bit of knowledge and be safe, and maybe you’ll decide that fasting is not the right fit for you right now.
What Intermittent Fasting Actually Is
At its simplest, intermittent fasting just means you’re creating a daily window of time where you eat… and a window of time where you don’t.
That’s it. You may eat during an 8 hour period, then no food or snacks for 16 hours. You’re sleeping through 8 of those 16 hours so it really isn’t that long. Example: You eat from 7am to 3pm, then don’t eat again until 7am.
But here’s where things went sideways for me and I have seen in others:
Most people were taught to skip breakfast, push food later, eat big at night, and call that “healthy.”
Biologically? That’s backwards. It feels easier to start with, but it does not match our circadian biology.
Your body is most prepared to digest, metabolize, and use food earlier in the day when cortisol, insulin sensitivity, digestive enzymes, and thyroid signaling are naturally higher.
A Better Way to Intermittent Fast
So if you’re going to fast, the healthier version looks like this:
Eat earlier. Fast later.
• Big, protein-rich breakfast like we talked about previously
• Solid lunch (I have a hamburger patty most days. I keep a stack of frozen patties ready to toss into the air fryer. Easy to make, eat and clean up)
• Light early dinner or stop eating mid-afternoon
• Fast from mid-afternoon until breakfast the next morning
This still gives you a 14–16 hour fasting window but it respects circadian rhythm instead of fighting it.
Eating earlier also helps sleep. When you go to bed with a full stomach, your body is still digesting and digestion takes priority over deep sleep and repair. Those processes get postponed until digestion is done. When food is finished earlier, your body can shift fully into sleep mode. And girl… we need our sleep to be top quality.
By eating earlier in the day you’re telling your body that “Food is available and we’re safe.” We want those safety signals. This matters more than calories.
Why This Works Better (Especially for Women)
When you eat earlier in the day:
• Insulin sensitivity is higher
• Cortisol rhythms stay intact
• Leptin signaling improves
• Thyroid signaling stays supported
• Evening food noise drops
• Sleep improves
And yes, you still get the metabolic benefits people want from fasting… without pushing the body into conservation mode.
This is the difference between metabolic flexibility and metabolic stress.
Who Should Be Careful With Fasting
This is the part people don’t like to talk about but I am going to anyway because I see it too often.
Intermittent fasting is not appropriate (or should be used very cautiously and with your doctor’s oversight) if you:
• Consistently eat under ~1,400 calories (PLEASE eat enough, ladies)
• Have low appetite or rely on hunger suppression (GLP-1s, stimulants, peptides)
• Are losing hair, muscle, or body temperature
• Feel wired-but-tired
• Have sleep issues
• Are recovering from illness, surgery, or rapid weight loss
In these cases, fasting doesn’t create resilience or any of the other benefits we are hoping to gain. All is does is compounds stress. I cannot tell you the number of women who tell me they are losing their hair, and when I look at their food, they are eating 900 calories a day. Truly, no enzyme, peptide, or supplement fixes chronic under-eating. Fasting on top of that just digs the hole deeper. Make sure you are fueling your body well before you even consider fasting.
Fasting Works Best When You’ve Already Fed the Body Well
Here’s the part almost no one teaches. I do Dr Sean OMara, Candi Frazier and Carnivore Amy just to name a few who discuss how important it is to feast, to have nourished your body well before considering fasting.
Fasting only works well when the body trusts that food is coming.
That trust is built by:
• Eating enough
• Eating earlier
• Eating protein consistently
• Maintaining muscle
• Sleeping well
If someone is already well-fed, metabolically stable, and eating enough overall? Short daily fasts or occasional longer fasts can be very beneficial.
If someone is already depleted? Fasting just teaches the body to hold on tighter.
The Bottom Line
Intermittent fasting is just another tool in the tool box. It may not be the right tool for you. Skipping breakfast and calling it discipline isn’t the win some people think it is. I was guilty of this for months. Like I just said, it is a good way to dig a deeper hole.
If you want the benefits of fasting whether it is intermittent fasting or longer fasts, you NEED to work WITH your biology.
In the next post, we’ll talk about how to prime your body for fasting so it’s supportive instead of stressful.
And yes… breakfast will still be involved. 😉 Here is a Frittata Recipe for you to enjoy:
Disclaimer: Linda is a holistic nutritionist. She is not a medical doctor. The content shared in her newsletters, posts, and blogs is for educational and informational purposes only and reflects her experience and interests. It is not intended as medical advice. Always consult with your qualified healthcare provider before making changes to your diet, supplements, or lifestyle.
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