OMAD, which stands for “One Meal A Day,” is a diet approach aimed toward shedding some pounds and improving certain aspects of health. 

It’s a branch of intermittent fasting where you allow your body to go 23 hours without food (including sleep time) and then you eat only one meal per day, typically during a 60-minute period.

And like many diet approaches, there is plenty of opposition when it comes to the decision to implement the one meal a day regime. 

But let’s dissect this approach so that you can have a better understanding if you were considering OMAD, or if you’re already implementing it…

Note: OMAD is not recommended for everyone and especially those with certain health issues. So, always consult with a medical professional before making any drastic changes to your diet. 

Potential Benefits of OMAD 

Weight/fat loss

Eating one meal a day will help anyone to lose weight simply due to the fact that most people will consume fewer overall calories this way (although, there are exceptions to this). We have to consume fewer calories than our bodies need to maintain certain body weight, in order to lose weight.

So, for example, about 3,500 equals one pound of body weight whether lost or gained. Well, to lose weight you’d have to ensure that your total daily energy expenditure (TDEE) exceeds your caloric intake consistently to maintain a deficit; which is required for weight loss. (1)

Health

Evidence for the efficacy of eating one meal a day for improving health is very mixed, although there are some positive effects associated with fasting in general.

One study had one group of healthy, normal-weight adults eat 1 meal a day and another who ate 3 meals a day. The 1 meal a day group experienced higher blood pressure, an increase in cholesterol levels (HDL and LDL), and a significant increase in hunger. 

However, subjects also experienced also a large reduction in fat mass and lower cortisol. (2)

And according to a different study, intermittent fasting is an effective approach for staving off and improving type-2 diabetes, while reducing body weight as well. And although the study followed the 16:8 protocol, there would have to be some positive effects for the 23:1 approach as a result of the fasting state. (3) 

Check out our intermittent fasting calculator to make reaching your goals way easier…

But interestingly, one published article of scientific literature suggests that the positive effects of fasting may be from a reduction in calories rather than putting it all down to the actual act of fasting and the potential effects on the body. (4)

Brooke EnceThe reason for this belief is that most fasting studies performed on animals show that a reduction in calories in what prolongs life and decelerates disease, as opposed to when the animal subjects fasted and then followed it with a period of eating without limitation which did not provide benefits.

Although, this same article talks about how fasting results in ketosis which is a bodily process that forces your body to use fat stores as its main source of energy. This also has benefits for slowing brain disease. 

So, there is at least the keto benefit of fasting for weight loss and possibly improved cognitive function.

But stable glucose levels are one concern with fasting which we’ll brief you on shortly. 

OMAD definitely isn’t for everyone and there are many variables that have to be considered to simply say OMAD will cause negative effects for everyone.

Convenience

Another very notable benefit of fasting, in general, is that it alleviates the stress of having to plan and prep your meals. Therefore, you can go on about your day and only have to worry about chowing down for a small part of the day.

Potential Disadvantages of OMAD

While there are some notable benefits, there are also disadvantages. 

For instance, if you’re trying to put on as much muscle mass as possible or gain a ton of strength progressively, then OMAD may not be for you. Now, you can make up for the calories that you did not eat during the 23 hours of fasting for the 1 hour you can eat, in order to maintain/improve performance and your desired physique. 

But, this isn’t sustainable for a lot of people who are trying to progress at a decent pace.

Sure, you can force all of your calories in all at once. But, it can be a challenge after you’ve reached a certain level of physical fitness. Although, the majority of elite-level bodybuilders, powerlifters, or athletes in general who engage in extremely intense physical activity would not even think of adopting such an eating regime. 

But, we just have to point out the different possible variables with OMAD and the very active individual. 

Light-headedness can also become a problem due to going so long without food which can be hard to manage especially when engaging in relatively challenging activities. 

But this can often be caused by unstable blood sugar levels which is a big problem when going long periods without eating. We need glucose to sustain brain function and to maintain healthy blood sugar levels. 

So, this is something else to consider if you’re an active individual.

Also, we can’t ignore the potential health risks associated with strenuous dieting like nutrient deficiencies and potential for the exacerbation of health issues.

But one big issue which can arise from eating only one meal a day is bingeing during the one hour that you can eat. Some people may not have the self-control to do OMAD in a healthy manner whether it be overeating and/or eating as many unhealthy foods as possible.

Well, this would be counter-productive. 

Foods To Eat On OMAD

You can eat whatever you darn well please as there are no rules regarding this aspect of OMAD. But does that mean you should?… no. You should always include healthy options for the majority of your daily diet regime.

Our bodies need certain nutrients to perform and maintain healthy functioning which is only possible by consuming nutrient-rich food sources.

So, while you can cheat a little every now and then to satisfy your palate, try to eat more of the following food sources… 

• Greens
• Lean meats (unless vegetarian or vegan)
• Plant-based foods
• Low-fat dairy
• Sweet potatoes
• Berries
• Nuts and healthy oils
• Natural foods in general

Check our article on healthy food choices.

Is OMAD Safe and Effective Long Term?

This will depend on the individual as no eating regime is effective or healthy for everyone. For many, eating one meal a day is just not sustainable but on the other side of the spectrum, many people make OMAD a lifestyle.

There’s no sure answer for this but lifestyle factors and current health will determine whether or not someone can implement OMAD long term.

Who Should Not Do OMAD?

While most healthy human beings can implement OMAD whether it be short or long term, there are many who should not do OMAD.

The people who should avoid include:

• Children
• Young adults
• Pregnant women
• People with diabetes
• People who have/had an eating disorder

If you do have any sort of health condition, you should always seek the advice of a medical professional before implementing any diet routine which may deprive you of nutrients for an extended period of time. 

Final Thoughts

If OMAD works for you and you’re healthy as a result, then we can’t convince you of a reason to not continue. This form of intermittent fasting has its benefits but there are many potential negatives as well.

So, if considering (or if already doing) OMAD, take the necessary safety precautions and make smart decisions regarding how you approach it.