How Much Weight Can You Lose On One Meal A Day?

I was doing OMAD for 3 months and lost 25 lbs (that’s around 2 lbs per week). Some people may see results a little faster (even up to 3 lbs per week), and some slower.

Your progress can depend on a number of factors, for instance, your age, gender, physical activity, and stress levels, according to experts.

This article explains how much weight can you lose on one meal a day, and gives tips on how to lose weight safely.

including dietary factors to avoid and exercise guidelines.

I lost 25 pounds by eating only dinner a day

Like most overweight men in my age, I wasn’t proud of carrying around all that extra belly fat. I wanted to lose at least 2-3 lbs per week and maintain my weight loss for as long as possible.

When I started OMAD, my plan was to only eat one meal (usually late lunch, or dinner).

The reason why one meal a day sounded so appealing to me was becasue it offered relatively quick results.

I wasn’t concerned about making this process sustainable (a big mistake). The biggest fear I had before starting OMAD was how much weight I can lose as most of the diets in the past have failed me.

How much weight can you lose?

my one meal a day

The Centers for Disease Control and Prevention explains that it’s natural to have the desire to lose weight faster.

They recommend that loss takes time and people who lose weight at a steady pace are more likely to keep the weight off.

The CDC also states that a person can safely and effectively lose about 1–2 lb a week, which is around 4-8 lb per month.

What factors determine weight loss

According to the United Kingdom’s National Health Service (NHS), weight loss is a result of many factors which have a cumulative effect on the individual, rather than one single aspect.

In other words, each person may respond differently to eating only one meal a day, depending on:


The NHS states that poor eating habits, comfort eating, and alcohol – all can lead to consuming more calories than usual.

Physical activity

According to NHS, in western world society, many people have sitting jobs, drive cars, and spend most of their leisure time being inactive.

The lack of physical activity means that the calories people consume can end up being stored in the body as fat.


The NHS states that in some cases, the stress hormones (adrenaline and cortisol) can make it harder for insulin to do its job in controlling blood sugar, which can trigger food cravings.

The key is to find ways to relieve stress without overeating.

How much weight can you lose on OMAD?

Many intermittent fasting experts, including Dr. Grant Tinsley, an associate professor at Texas Tech University, confirm that OMAD and TRF are increasingly becoming popular for weight loss and overall health. 

“Eating one meal a day (which would consist of approximately 25% of daily calorie needs) for 3 to 12 weeks can reduce body weight by 3% to 9%, body fat by 3 to 5.5 kg, and favorably improve blood lipids by 5% to 20%,” according to Dr. Tinsley.

Let’s map out an example to make those numbers easier to picture:

If you’re an overweight male who weighs 220 pounds, you can lose between 6 to 20 pounds of body weight in 3 to 12 weeks on OMAD.

If you’re an overweight female who weighs 180 pounds, you can lose between 5 to 16 pounds of body weight in 3 to 12 weeks on OMAD.

“Intermittent fasting creates a caloric deficit where the body switches from using energy from food to stored body fat,” says Dr. Tinsley.

For me, the hardest part was to stay consistent. Eating only one dinner per day made me feel so hungry all the time.

I also felt I was having a hard time being social with friends. For example, I stopped eating desserts or drinking alcohol. (Basically, I felt like I wasn’t living a normal life).

First week

In my first week of eating one meal a day, I lost around 3-4 pounds. However, this wasn’t my first rodeo. I understand that most of my initial weight loss is not due to fat burning, but rather water loss.

Jeff Volek, Ph.D., an expert in low carbohydrate research from The Ohio State University, says “the reduction of carbohydrates and sodium intake from diet triggers the body to release extracellular water”.

“When you reduce food intake, the body eliminates excess water due to the reduction of carbohydrates, and as a result, you see the weight drop on the scale,” says Dr. Vokek.

However, this effect is temporary.

“For every gram of carbohydrates, you will retain around 3-4 grams of water, and once you reduce the intake, that extra water goes away,” Dr. Vokek explains.

I’ve created a simple graph (see below) to help you illustrate this process.

how much weight can I lose on omad in a week
  • On your left side, you see a glucose gram that binds with 3 grams of water.
  • On the left side, you see that a lack of glucose leads to a lack of water retention.

Let’s look at this from the perspective of a person (see below).

can I just have meal replacement shakes
  • On the left side, you see a visual graph with a person who consumes more carbs that is filled up with water.
  • On the right side, you see a similar graph with a person who consumes fewer carbs, so he/she retains less water in the body.

I had the same effect during my ketogenic diet experiment, where according to my body fat analysis, in my first week I lost over 7 pounds, but it was all water weight.

The actual fat loss took me much longer than a week.

Below you can see the video from Mike Thurston about how much body fat can you (realistically) lose in the first week.

How much water weight do you lose before losing fat?

Water weight loss is a well-known fluid and sodium manipulation and carbohydrate loading technique.

Some pro bodybuilders reduce carb intake just before the competition, so the extracellular water expels from the body.

Then, around 48-24 hours before the bodybuilding competition, athletes load with carbs so the muscles can absorb all the glucose together with water, and in the results, the muscles appear to be bigger.

Janelle McNeil-Masuka, MD, an anesthesiologist from North Carolina, says “the exact amount of water weight you lose before losing fat is unmeasurable”.

“On average, a healthy adult can lose between 600 to 800mL of water per day. Around 300 to 400 ml of water loss is done via diffusion through the skin, and around the same amount is lost via the respiratory tract,” says Dr. Masuka.

First month

In my first month on OMAD, I lost 15 pounds of body weight. I also noticed that my weight didn’t go down in a linear way.

I thought will be able to maintain my average weight loss of 2-3 pounds per week. Instead, it was rapid in the first 20 days, then I slowly hit the weight loss plateau.

I saw some success stories and jaw-dropping before and after pictures where people were losing 3-4 pounds per week and staying consistent for a number of weeks.

What results can you see in the first month on OMAD?

One month of OMAD is enough to see visible changes in the body. In general, one meal a day starts to work within the first days, but the changes are so small that are unable to be seen.

It’s impossible to see any changes on day one.

I don’t know how much weight people normally lose, but I was happy with my results after one month. It helped me to eat less, even after I came back to regular eating.

Results after 3 months of OMAD

Here you can see my picture of doing OMAD for 3 months. As you can see, I’ve even managed to put on some muscle.

one meal a day for 30 days

How did I do it?

This was a combination of one meal a day and normal eating. On some days I would eat just one meal, but on others, I would eat regular meals.

The most important for me was food choices, where I was eating more satisfying foods.

  • I would eat meats that are high in fat to keep me full for the entire day (see picture below).
  • I ate things like pork chops, pork necks, and pork joints. (I rarely eat fish, tofu, or other low-calorie foods.)
  • I was eating slowly and timing my meals to make sure I spend at least 20-25 minutes. This way I was fuller with less food.
  • I kept journaling my food intake and focused on how I felt when I’m not eating. This helped me to tune in to my body signals, and realize that hunger is just a feeling. And it’s not an emergency.

Lessons learned

my one dinner a day with satisfying protein sourses
I eat lots of steaks, pork, and chicken

The more consistent you are, the more weight you will lose. Here are the things that I learned from this 3 months experiment with OMAD.

My self-awareness got better

I realized that I was using food to comfort myself in stressful situations (reaching out for food under pressure, eating more during emotional situations, etc.)

So by eating one meal a day, I was “forced” to find new ways to manage my stress, without eating more (meditation, planning my day, physical activity, etc.)

To help you understand how this works, I made a simple diagram (see below).

how much weight you lose on omad will depend on your eating behaviors

Eating only a dinner a day helped me to notice that I was using food not only to satisfy my hunger but also to:

  • reduce stress;
  • escape from boredom; and
  • regulate and control my emotions.

For the best weight loss results on one meal a day, you need to stay consistent and be able to tolerate stress without eating.

Start by noticing how you feel when you’re not eating. See if being hungry is a deal-breaker (or it’s not an emergency).

I also realized that eating one meal a day is hard to do because it requires more “skin in the game” compared to the other intermittent fasting approaches. (This basically means that one meal a day is not for everyone.)

This process takes time

Another lesson I’ve learned from my one-meal-a-day experiment is that sustainability is the key.

Sustainability means you should not focus on the results. Instead, focus on the behaviors that can deliver your results.

You can follow the American Heart Association (AHA) approach (which is realistic and achievable).

These steps (see graph below) can help you lose weight on one meal a day more easily by balancing healthy eating while becoming more physically active.

ways to make the one meal a day more sustainable

Start tracking your food intake

Keeping a food journal and recording what you eat can help you improve your self-awareness. You don’t need fancy fitness apps or food scales.

Just write down what you eat, as well as notice your thoughts and emotions around eating times (and when not eating).

Set realistic goals

Setting specific, measurable, achievable, realistic, and time-bound (SMART) goals can make you stay on track.

  • give your weight loss goal a number (10 pounds, 15 inches, etc.)
  • set a reasonable duration (end of summer, Thanksgiving holiday, etc.)
  • have a beginner mindset and start small (walking 20 minutes a day, eating protein with each meal, etc.)
  • take body measurements (use skinfold calipers, measuring tape, bioelectrical impedance analysis, etc.)
  • keep a photo journal (take a picture once a week, ideally in the same place with the same lighting, and write down the date)

Basically, spend time and map out all the processes in actionable steps (behaviors) that will eventually lead to the results.

You would be surprised how powerful goal setting is, especially when you make a commitment and stick to it.

Watch your portion size

It’s always a good idea to watch your food portions. Start by slowing down and spend 15-20 minutes (or more) on your meal.

If needed, pause every 5 minutes to assess how satisfied you are. Try to avoid eating when rushed, stressed, or in the middle of doing something else (driving a car, watching TV, etc.)

Get active

Start by figuring out what activities they enjoy doing. I recommend starting with what you feel comfortable with and don’t worry about being “perfect”.

Instead, try to have a beginner mindset and aim for being “a little better”. Over time, aim to move more, with more intensity, and sit less.

The AHA also suggests having a conversation with your physician, finding a compassionate doctor with expertise, or getting support from your social circle.

I started to organize my eating environment

Making smart choices is the key. A healthy kitchen makeover is a good way to start. Get rid of foods that can trigger you to overeat.

how much weight can you lose on omad in a month

Make a list of foods that you enjoy. Clean up the clutter and ensure your cooking station is always at your disposal.

Some studies show that modifying your environment to support your weight loss program leads to substantial results.

This includes having your home, workplace, and daily behaviors organized in favor of fat loss and are identify any triggers that can cause unwanted behaviors.

Why not create a list of things that you know are triggering your unwanted behaviors, together with a list of things that you know trigger your best behaviors?

In other words, try to “find out” what causes you to get off track.

One of the exercises I started doing with my wife was the traffic light system.

This is a very simple way to keep you focused and create consistency while doing any form of intermittent fasting, especially OMAD.

how to maintain weight loss on OMAD after 3 months

Think of a traffic light on the street. You have red, yellow and green. So write down three lists and mark each list accordingly.

The red list means stop, unsafe to go. Yellow means caution. Green means “safe to go”. You can apply this to situations, thoughts, emotions, food, people, and the environment.

Red lights

Those are the situations, people, places, or events that spin your dials. You become the worst version of yourself. Those are the situations in which you do things that you don’t want to do, say or think.

For instance, if you have a certain food in your house you always seem to overeat. Or if you go out to a certain place you always seem to drink more.

Yellow lights

Yellow lights are the situations, places, people, or foods that can be either good or bad. For instance, shopping in the mall at 10 am may feel relaxing but at 5 pm is really stressful. Or working with X person may feel like a blast but with person Y you just hate your life.

Green lights

Green lights situations are always awesome. They never trigger any problematic thoughts, behaviors, or mindsets. In fact, green light situations, foods, people, places, and environments trigger you to make better choices.

(Maybe even without you realizing it.)

For instance:

  • it can be a meeting with a certain person;
  • eating at some specific restaurant;
  • listening to your favorite music while you working out, or
  • 10-minute yoga stretches out the anxiety.

The List

Use the list below to organize your eating environment.

trigger list

Once you’ve your red, yellow, and green lists, you can now easily identify all your good and bad triggers. This will help you make better choices and avoid losing control even when you’re on OMAD.

Therefore you can stay consistent.

Several factors will either enhance or slow down your weight loss results on OMAD. It will strongly depend on your gender, age, physical activity, stress, motivation, mindset, and having too high expectations.

Some things are out of your control (age, free time, etc.).

However, things that are in your control are usually the ones that move the needle the most.

So focusing on your daily behaviors will allow you to get more momentum, reduce stress and direct your energy on your goal.

The process will take time. So don’t stress or panic if you don’t see the results in the first week.

Go Further with OMAD

This article is part of the OMAD: What To Eat To Stay Full For Longer

In the following articles, I show you all the related aspects necessary to get started with OMAD and know what to eat for the best results.

Learn More: Click here to learn more about omad meals

Michal Sieroslawski

Michal is an exercise physiologist (MSc) and a veteran endurance athlete. He loves to experiment and share his successes and failures to help busy men and women who want to lose weight.

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