So there’s actually a whole sub for it r/OmadDiet. But yeah, you need to be pretty strategic with your food choices. Not only are you trying to get all your calories in one meal - though lots of folks are trying to lose weight and thus eating at a deficit, but also all your balanced nutrition. A lot of OMAD meals end up being a main meal a like a smaller side meal for variety, and typically you give yourself more like an hour to eat it all not strictly one sitting. If you focus on good nutrient dense foods it’s not too hard to get enough food.
During weight loss I was on an OMAD pattern most days per week. I tried to be sure to eat enough protein each day but otherwise just ate to satiety. Whatever that happened to be. There’s no need to hit a calorie target and I didn’t track or care about the calorie count. If your metabolism is working you’ve been “eating” your body fat all day, which is of course the point if losing weight is the goal. It’s why the pattern is sustainable. We evolved to in fact thrive on body fat during periods of food scarcity.
So I found that I’d eat more than my pre-IF typical dinner but it was maybe 25% more. I would often snack a bit while cooking. And if hungry after dinner I’d add cheese or nuts until satisfied.
OMAD = One Meal A Day.
You fast for 23 hours and then you get to eat.
I’m an athlete myself and I have been doing OMAD every day for at least 6 months and it’s really beneficial as long as you keep track of your macronutrients.
The point of fasting is burning stored calories vs eating calories. So let’s say your body needs 2000 calories a day. If you eat 1000 calories when you get to your fasting state your body will consume 1000 calories from storage to get that 2000 needed.