I Tried OMAD for 30 Days. My Doctor Asked If I Was Okay.
One meal a day. That's what OMAD means. It's the extreme end of intermittent fasting — the 23:1 protocol where you eat all your calories in a single hour and then fast for the remaining 23. I had been doing 16:8 for six months. Skipping breakfast, eating lunch at noon, dinner at 7, feeling pretty good about myself. Then I fell down a Reddit rabbit hole.
r/OMAD. 340,000 members. Before-and-after photos that looked like magic. People claiming mental clarity, fat loss, autophagy, longevity. "Your body was designed for feast and famine," they said. "Three meals a day is a marketing invention." I read the studies. The Valter Longo research on fasting-mimicking diets. The Satchin Panda circadian rhythm work. The rodent studies showing extended fasting reduced inflammation markers. I was convinced. I was also bored with 16:8 and wanted a challenge.
So I did it. One meal a day. Every day. For 30 days. I tracked everything. Weight. Body fat. Energy. Sleep. Mood. Workout performance. Blood markers before and after. I was going to be the data point that proved OMAD was either brilliant or terrible. And I was going to do it right.
Day 1-3 were fine. Hungry, but manageable. I ate at 6 PM. A massive meal — 1,800 calories of chicken, rice, vegetables, olive oil. I was stuffed. Then I fasted. By 10 PM, I was already thinking about breakfast. But I didn't eat. I drank water. I went to bed. I woke up at 7 AM and felt... normal. Not great. Not terrible. Normal.
Day 4-7 were harder. My workouts suffered. I train four days a week — strength training, nothing extreme — and by day 5, my squat was down 15%. My energy crashed at 3 PM. I was irritable. Short with my wife. Short with my kids. I snapped at a barista who got my order wrong. That's not me. Or it wasn't me, until I hadn't eaten in 19 hours.
Day 8-14, something shifted. The hunger lessened. Not disappeared — I still thought about food constantly — but it became background noise instead of foreground screaming. My energy stabilized. I wasn't crashing at 3 PM anymore. My sleep, which had been fragmented, improved. I was falling asleep faster and waking up less. I started to understand why the Reddit people were obsessed.
But the social cost was real. I couldn't eat lunch with colleagues. I couldn't have coffee with a friend without explaining my "eating window." My wife, who is supportive but also realistic, told me I was becoming boring. "All you talk about is fasting," she said. She wasn't wrong. When your entire day revolves around one meal, that meal becomes an obsession. I planned it for hours. I watched cooking videos at 10 AM while fasting. I was hungry and fixated and not particularly fun to be around.
Day 15, I got my blood work done. I was curious about the metabolic effects. Fasting is supposed to improve insulin sensitivity, reduce inflammation, lower triglycerides. My results came back mixed. Glucose was down — 82 mg/dL, excellent. Insulin was down. Triglycerides dropped from 110 to 78. But my cortisol was elevated. My thyroid markers (TSH) had risen slightly. And my LDL cholesterol had increased by 12 points. Not dramatic, but not the universal improvement I had expected.
I called my doctor. He's a pragmatic guy. Doesn't buy into wellness trends. He looked at my numbers and said, "You're not dying. But you're stressing your body. The elevated cortisol and TSH tell me your body thinks it's in a famine. Because it is." He asked if I was planning to do this forever. I said no. He said, "Good. Because forever is a long time to eat one meal a day."
Day 16-23, I modified. I added a small protein snack at 2 PM — a Greek yogurt, about 150 calories. Technically breaking OMAD, but I didn't care about purity. I cared about sustainability. The snack helped. My workouts recovered. My mood improved. My wife stopped threatening to hide my fasting app. But I was no longer doing OMAD. I was doing 20:4. Which is fine. But it's not what I set out to test.
Day 24-30, I went back to strict OMAD for the final week. The hunger was easier. The workouts were still down. I lost 4.2 pounds total. Some fat, some water, probably some muscle. My body fat percentage dropped from 18.2% to 17.4%. Not dramatic. Not life-changing. But real.
Here's my honest assessment. OMAD works for weight loss. It works because it creates a calorie deficit. It's hard to overeat in one hour. Not impossible — I managed it a few times — but hard. It also works for some people because it simplifies decision-making. One meal. No snacks. No "what should I eat?" It reduces the cognitive load of eating.
But it's not magic. The autophagy benefits are real in rodents, but unproven in humans at this protocol. The longevity claims are speculative. The mental clarity some people report is likely just ketones, which you can get from a 16:8 fast without the social and hormonal downsides. And the muscle loss risk is real if you're not hitting your protein in that one meal — which I struggled to do consistently.
Would I recommend OMAD? To some people, maybe. If you have a lot of weight to lose, if you don't care about maximum muscle retention, if your social life can handle it, and if you understand that it's a tool, not a lifestyle. But for most people? 16:8 or 18:6 is probably better. Easier. More sustainable. Less cortisol. Less obsession. More life.
I went back to 16:8 after day 30. My doctor was relieved. My wife was relieved. My barista was relieved. And I was relieved too. I like breakfast. I like lunch. I like not thinking about food as a countdown to 6 PM.
— Sarah, from a kitchen in Austin where there are three meals a day and no fasting apps
P.S. I kept the 4.2 pounds off. But I also kept the habit of not talking about fasting at parties. That was the best improvement.
