I Ate One Meal A Day For 30 Days

Check out my client Ben’s transformation where she lost a whole bunch of fat and achieved her target weight!

What would happen if you only ate one meal a day for the next 30 days? Would you lose weight? More specifically, would you lose body fat or muscle mass?

Maybe your body would go into starvation mode and cause you to gain weight rather than lose it due to a slower metabolism?

Here’s what I discovered.

I’ve been eating one meal a day almost every day for about 2 years now, and it’s worked well for me. Let me tell you the results you can expect if you stick to only one meal day for the next 30 days.

Additionally, I’m going to share scientific studies and evidence that will help you see the pros and cons of this diet. 

But, first, I will explain the proper way to set up this diet plan for yourself

#1 Creating the diet plan

There isn’t an abundance of information available on the one meal a day diet like with intermittent fasting. So, many people who try to stick to this diet plan mess it up from the get-go and turn it into more of a warrior diet. 

The warrior diet is great, but that’s not what the OMad diet is about. A warrior diet is where you fast for 20 hours of the day and eat in the 4-hour feeding window. If you don’t set limits to the amount of time you spend eating, you can easily drag out one meal into a buffet that lasts for hours. 

It’s very important that you understand that one meal a day is also a 23/1 fasting to feeding split i.e. you give yourself a 1-hour feeding window, usually during the same time every day, and spend the remaining 23 hours of fasting.

#2 OMAD creates a calorie deficit

If it isn’t already obvious, OMad, or the one meal a day diet, helps you create a calorie deficit without restricting calories. When you’re only eating once a day, in the right way and limit it to under an hour, you can only fit so much food into your stomach before you’re full.

Join 30,000+ people that have changed their bodies and lives with my Free 6 Week Shred

Essentially, we’re limiting calories by decreasing meal frequency which can immediately be a red flag for those that believe their metabolism slows down instead. However, numerous studies have proven this to be a myth.

One study called “Meal Frequency and Energy Balance” (1) combined and examined research from many unique case studies on the topic of meal frequency. The researchers found that a nibbling pattern of eating or eating more frequently didn’t present any advantage as far as the metabolic rate was concerned.

Your metabolism will remain the same

Your metabolism is not going to automatically slow down from eating only one meal a day for 30 days. If you have the same amount of calories in that one meal as you would in 6 meals then your metabolism would remain the same in both situations.

But, does that mean the “starvation mode” that we’ve all been warned about is a big scam? Well turns out, it’s not. It’s actually called adaptive thermogenesis and it’s a very real body response.

In response to decreased energy intake, your body will reduce energy expenditure to avoid starvation. However, adaptive thermogenesis will occur based on the total amount of energy or calories consumed.

As long as you don’t perform fasting for over 48 hours, It doesn’t matter if those calories all come in at once or throughout the day. Shorter fasts that last under 48 hours have been shown to increase your metabolism (2) between roughly 4 to 14 per cent due to an increased norepinephrine concentration in the blood. (3)

#3 What about weight loss?

The thermic effect of foods suggests that you lose more weight when you have more meals throughout the day. This simply means that digesting food all day requires more energy which should raise your metabolism, right?

According to a meta-analysis (4), and most studies on this topic, meal frequency does not affect weight loss. If it did affect weight loss, then you would lose more weight eating 6 times a day than you would by eating 3 times per day.

Join 30,000+ people that have changed their bodies and lives with my Free 6 Week Shred

Luckily, there was a small study done where they compared one group that ate 3 meals a day to another group that ate the same amount of calories in 6 meals per day. (5)

It turns out, once again the researchers found no difference in weight loss, fat loss or appetite between the two groups. Granted, the low meal frequency group was still having three meals per day which, for many people, would be a lot easier to stick to than 1 meal per day.

#4 Case Study

The number of calories given to both groups (three meals per day and one meal per day) was intended to be a range set for maintenance, not weight loss and that’s exactly what happened throughout the 6 months both groups maintained their weight within 2 kilograms of their starting weight. (6)

Both groups also had similar responses with their hormone levels. Even Ghrelin, the hunger hormone, remained the same for both groups. This means, hormonally speaking, both groups should’ve reported the same hunger levels.

However, the one meal a day diet group did report ratings of slightly higher hunger levels. This may be because they were tested in the middle of the day before they had their meal.

Most subjects in the one-meal group reported extreme fullness after eating. Therefore, the results would probably be very different if they asked about hunger in the evening, post-consumption.

Join 30,000+ people that have changed their bodies and lives with my Free 6 Week Shred

The resulting difference between both groups

But, one major difference between the two groups was that the one-meal-a-day group lost more fat mass than the three-meal-a-day group, which is very interesting. This could be explained by the fact that they were consuming 65 fewer calories per day than the three meal group. But, 65 calories aren’t all that much.

Researchers believe that this change in body composition may have been also influenced by the effect that eating patterns could have on metabolic activity. They talk about a study done on rats that compared a nibbling diet to one that consisted of 1 large meal per day.

The rats in the one meal per day group developed an increase of free fatty acids from fat deposits and an increase in gluconeogenesis. This refers to a metabolic process where glucose is generated from sources other than carbohydrates such as fatty acids.

Sure enough, in this study, it does appear that glucagon levels were slightly elevated for the one meal a day group. Glucagon has the inverse function of insulin and helps break down fat for energy.

Insulin was also slightly lower in the fasting group, but not by a significant amount. Regardless it’s interesting that fat mass reduced more in the one meal a day group. Further research is necessary to support this finding.


At the very least, this study helps support the fact that you won’t slow your weight loss or fat loss by eating just one meal compared to more meals. You’ll probably speed it up. You see in this study the participants in the one meal group were forced to eat the same amount of calories as the three meal group even if they were full.

They would normally have eaten less and this is supported by rat studies that show rats only eat once and decrease their caloric intake by 10 to 30 per cent per day. These rats maintain a lower weight than the other rats that nibble throughout the day. This is why I like one meal per day, it naturally helps you limit your calories because of feeling full.

Join 30,000+ people that have changed their bodies and lives with my Free 6 Week Shred

#5 Is this diet suitable for everyone?

However, this diet is not for everyone. Researchers claim that the normal withdrawal rate for human feeding studies at their facility is 4 to 7 per cent. However, in the one-meal-a-day group, the withdrawal rate was an alarming 28 per cent. However, this could be up to chance because 5 participants withdrew from the one meal group due to prior health reasons.

Join 30,000+ people that have changed their bodies and lives with my Free 6 Week Shred

Only one person from each one meal and the three meal group withdrew because of the diet structure. Regardless, it makes you suspect that eating one meal per day may not be right for everyone.

It is true, some people may feel extremely hungry only eating once per day, and they could also binge in a very unhealthy way when they do get to eat. However, I’m sure there are people, just like me, that can benefit from eating only one meal per day.

Once you adopt this diet over 30 days, you’ll experience more mental clarity, be more productive, and probably lose weight and body fat as long as you don’t make dumb food choices at the end of each day. 

You won’t lose muscle mass, slow your metabolism, or die if you simply eat once during the day. As long as you eat clean single ingredient foods, this diet will help many of you find more time throughout the day while burning more fat.

Final Words

That about wraps it up. If you’re looking for a solution to lose some weight and burn some fat fast, you can sign-up for my 6-week challenge where my clients are losing 20 pounds or 5 per cent body fat in only 42 days through the link below.

Join 30,000+ people that have changed their bodies and lives with my Free 6 Week Shred

Within the challenge, we go over different diet approaches including fasting protocols all of which can help make this a permanent change for you. The program also comes with multiple customized diet plans, a recipe book, a daily workout plan, and an accountability coach to guide you through the whole process. 

The best part is that you can have the whole challenge for free as long as you’re willing to follow through and do your part.


  1. Meal frequency does not accelerate or slow your metabolism:
  2. Metabolic response to 48-hour starvation:
  3. Resting Metabolism Increase from Short term fasting:
  4. Effects of meal frequency on weight loss and body composition (meta-analysis):
  5. 3 meals per day vs 6 meals a day does not affect weight loss:
  6. One meal a day vs three meals per day for 6 months:

Join 30,000+ people that have changed their bodies and lives with my Free 6 Week Shred