OMAD - Why do people eat this way?

It would never work for me.

But my husband unofficially does this most weekdays. He is very much a routine oriented person, and when he is busy: he does not think about eating. He works mostly in his car, and his car is a strictly no eating zone. That plays in as well. He gets up in the morning and has coffee (black) and does his morning routine. Then goes to work. Because he does not take a break or eat in his car (self employed) he normally does not eat during the day. Then he will have a huge (often more food than he really needs but that is another topic) meal in the evening. And possibly a late night snack.

Weekends are a different routine, so he typically eats 2 or even 3 meals on Sat and Sun.

If not eating lunch means you would have a hard time sticking to a reasonable # of calories in the evening for dinner, then don't skip lunch.

I reckon it might work for some. But I’m not willing to suffer the hunger while trying.

I’ve tried 2 meals a day. That’s ok as long as I’m not training in the morning. I need some god before training.

OMAD has been the main way for gaining most of the weight over my years of yo-yo dieting. Eating once a day, take-out junk food, at ludicrous quantities...and taking the rest of the day off to digest it lol.

I consume all my daily calories within a 2-3 hour time period starting from 7 pm. I managed to drop weight from normal weight to slim normal weight doing this last year. I'm still doing it because I simply like eating big meals (I also eat mostly low-calorie, high volume foods like veggies and fruits and low-fat dairy, so yeah, my meals are BIG) and have been maintaining for over a year now. I still count calories though. Actually I started using MFP again when I began eating this way, because I wanted to make sure I neither ate too much nor too little.

Rannoch3908 wrote: »

- I would like to know if OMAD means literally eat all 2000 calories at one meal or say just between 4pm and 7pm.

I've seen some weird "rules" about OMAD on the internet where you "have to" consume all the calories within an hour, and have a plate with a certain diameter, and only have a food pile on said plate of a certain height. I guess by these definitions (that I'm pretty sure someone just pulled out of their butt) I'm not doing OMAD. But basically I eat all my food in one go.

Rannoch3908 wrote: »

- I assume since it's not a diet - just a way of eating - that it doesn't matter if say on the weekends you eat 3 meals a day right?

As long as you stick to your calorie deficit it doesn't matter when or how many times a day you eat. It hasn't been proven that fasting or time-restricted eating has any type of extra weight loss benefits. Me, I eat a small breakfast if I have a run that's 2 hours or longer scheduled. (Other than that I don't eat before exercise and feel just fine.)

Rannoch3908 wrote: »

- What benefits does it give you (weight loss, health, hunger, energy, etc)?

As I mentioned above, it worked very well for me for weight loss. That's probably due to my personal psychological and maybe physiological quirks, and I imagine it wouldn't work for many. I usually don't get hungry during the day, or if I do, coffee or another hot beverage helps. I don't think that for me it's had any other of these numerous benefits that some adherents tout, though.

Rannoch3908 wrote: »

- What downsides do you experience from eating OMAD?

Well, I like eating this way too much, so it has dampened my enjoyment of having lunch socially. If I eat with other people, I'd rather it be later in the day just so I can stick to my habits.

It sounds like a way of eating that would be best suited to those who are naturally not hungry throughout the day or who have really busy schedules and often forget to eat. It doesn't sound sustainable if you're trying to force yourself into that way of eating simply to lose weight. At that point, it toes the line a bit too closely with disordered eating in my opinion. Ideally, you should eat when you're hungry and stop when you're full. If you're not hungry until dinner, fine. But I don't think that's most people.

I tried it. I'm still part of an OMAD group.
What I've seen is that it does help those that stick with it to lose weight/control weight a bit better. They get to still eat what they want, but since it's all in one big meal, they're not eating in a surplus and still get to eat whatever.
It's just a way that works for them.
For myself... I found myself WAY too obsessed with food when I was doing it. Physically, I was ok. The hunger pangs you get pass and it's really not difficult to do physically. Mentally though.. food was ALWAYS on my mind and I always got obsessed with making my meal 'worth it' and got upset if it wasn't.
If I naturally OMAD every once in a while b/c I'm busy, ok, but I just can't get myself to do it again. Just not something that works for me.

I actually knew a guy who did OMAD for at least 5 or 6 years (might still be doing it - we lost touch). This was before it was called OMAD. He was not fat at all - actually quite thin, a coworker with a very athletic/active lifestyle. I was stunned by the notion that someone would only eat once per day, but he said he didn't have time to work his 12 hr/day job, pursue all his interests, raise a family, and then waste 2 hours per day preparing and eating three meals. So he just ate one and was happy with that. When I asked if he was hungry, he said you'd be surprised, the less often you eat the less hungry you are when it isn't mealtime. Which I thought was a giant crock of s&&t at the time - one of those "easy for a thin person to say" things.

Fast forward to today, I eat noon to 7 pm, which is not OMAD. But I now agree with his observation. I used to wake up starving, and be starving all evening, and nowadays, the only time I'm generally hungry is between noon and 7 pm. Occasionally at 11:30 am as my brain tries to get ahead of me LOL

So I think the answer is, OMAD like other forms of TRE can help manage hunger, and like all other forms of TRE, the idea as far as how it works for weight loss is to compact your calorie consumption into a window so that it's easier to hit a calorie target. However, my n=1 data point is of a very thin, non-food-focused person. I know OMAD would never work for me. I love the eating parts of my day, and I think trying to narrow them down to an hour would leave me very dissatisfied. Seems to me that unless you fall into OMAD naturally, which must be quite rare, it requires an iron discipline that more laid back forms of TRE don't require of you.

If I'm in a diet so less to eat, I usually fall into OMAD just because of the schedule.
Well, 1-2 hr OMAD depending on how much to eat, if that still counts. Maybe that's a short IF instead.

Busy with things (now helping high risk friends with errands and my mom much more) and trying to get workouts in, dinner doesn't happen until 10-11 many nights, follow up with snack closer to midnight to finish off the calories. Up until 2 am usually so a few hours to digest before going to bed.
In which case yes lots of heat from all that processing, especially if hard bike ride and lots of carb-store filling.

If I'm in maintenance, then IF with about 3-4 hr window is fine, though dinner is still usually late, I may just get in some snacks prior to exercise, or if long ride then during.

I've been shocked how well I can still do a workout fasted after 18-19 hrs, what workout occurred the prior day has more an impact than the fast, in diet or maintenance.
And not hungry unless I do eat something during day.

It's made life slightly easier. No longer am I cooking 3 times a day or ordering food.

I realise you were only describing what works and how/why it works for you - but just on this point; although I eat usually 3 meals, 2 snacks per day (sometimes bit different on weekends) I am definitely not cooking or ordering food (you mean, buying take out food?) 3 times per day


Nearly always only eat one cooked meal per day - and if it is ever 2, one is cooked by someone else - eg some days at work cooked lunch is provided.

My breakfast and lunch consist of cold things like cereal, yoghert, fruit, crackers, sandwich.
Occasionally toast - which I guess is technically a cooked meal

nearly always only my main meal at tea time is a full cooked meal.