Man Tried Eating One Meal A Day For 7 Days And Shared The Major Impact It Had On His Body

One man decided to put the “One Meal a Day” diet, also known as OMAD, to the test and shared his honest thoughts in a video, and his experience might not go the way you would expect.

Instead of just talking about it, he actually followed the routine and documented how it felt day by day.

The OMAD diet is a type of intermittent fasting that is meant to push the body into burning fat for energy.

The idea is simple in theory, but intense in practice, because the person eats all of their daily calories in one main meal, usually within a one-hour window.

After that meal, they fast for the rest of the day and night until the next eating window.

Water and zero-calorie drinks are usually allowed, which means people often rely on things like black coffee or plain tea to stay hydrated and help get through the long stretch without food.

Content creator Will Tennyson decided to try the OMAD diet for a full week and recorded the process for his YouTube channel.

He tracked what he ate, how he felt, and how his body responded as the days went on.

He explained that he did not have a specific fitness goal going into it, but he was still curious to see whether his weight would go up or go down.

He also wanted to find out how many calories he could realistically eat in one sitting without feeling sick or overly stuffed.

He started the challenge with a huge Chipotle bowl and then went straight into a workout.

At first, he said OMAD did not seem to affect his training too much, since he normally works out without eating beforehand and “typically does train fasted.”

The One Meal A Day diet is exactly what it sounds like Getty Stock Images

Still, he said the biggest difference was that the gap between exercising and eating felt “super long,” which started to catch up with him.

He explained that he was “completely gassed” between his 11:00 a.m. workout and his Orange Theory session at 5:45, and he even had to “leave the class altogether” because he felt so drained.

Tennyson said he usually broke his fast around 3 p.m., and once that time got closer, food was basically all he could think about.

Then when it finally came time to eat around 6 p.m., he said he would feel like bingeing because he was so hungry by that point.

After four days, he admitted it was not “getting easier,” and he kept thinking about eating throughout the day.

To deal with the hunger, he ended up drinking more caffeine than usual, and he said he would go for walks and grab a coffee whenever the cravings hit.

He also realized how hard it was to stick to OMAD socially, because he could not easily grab food with friends like normal.

It made him notice just how much daily life revolves around meals, even when you are not thinking about it.

By day five, he said things started to feel “easier,” mainly because he learned how to tell the difference between “actual hunger and habitual hunger.”

He also noticed that what he thought was hunger was sometimes thirst, so he would drink water or have a black coffee instead.

By the end of the week, he lost 3.8 pounds, but he still described the whole experience as “extremely difficult.”

Even with the weight loss, he made it clear that the routine took a lot out of him mentally and physically.

Tennyson said: "Overall, it was not that great. It was just too extreme, and I just didn't find it to be too sustainable for myself. Probably not for a lot of people."

How does OMAD affect the body?

WebMD explains that when you eat carbohydrates, your body breaks them down into sugar, which then enters your bloodstream. This is part of how your body gets quick energy from food.

If there is extra sugar that your body does not need right away, it triggers the release of insulin. Insulin is a hormone that helps move that extra sugar into fat cells, where it can be stored for later.

During fasting, insulin levels start to drop because you are not taking in new food. With less insulin circulating, the body shifts how it powers itself, and fat cells begin releasing stored energy to help meet the body’s needs.

This switch in how the body fuels itself typically happens only after fasting long enough for insulin levels to fall significantly.

In other words, it does not happen right away, and the timing can vary depending on the person and what they ate before fasting.

Research suggests OMAD may have benefits for people who are trying to lose weight.

Research into the OMAD diet has been mixed Getty Stock Image

A 2018 research review found that intermittent fasting, including longer fasting windows like OMAD, is likely to lead to weight loss for many people.

Some studies also suggest it may support metabolism in certain ways, but experts say more research is still needed.

The long-term effects are not fully understood, especially when it comes to different lifestyles, activity levels, and health conditions.

Some possible benefits include feeling more alert, and some people find that eating earlier in the day and then fasting overnight can support weight loss. For certain people, it can also feel simpler to plan just one main meal instead of multiple meals and snacks.

But there are downsides too, and the diet can be hard to maintain for most people. WebMD notes that there is no clear proof that eating one meal a day works better than other methods for weight control, and it may leave you feeling hungrier overall. It also might not be more effective than simply reducing calories in a steady, balanced way.

A 2022 study published in the National Library of Medicine found that eating one meal a day was linked to a higher risk of dying from any cause, as well as death from cardiovascular disease. That finding has raised concerns about whether this eating pattern is safe for everyone.

There are also concerns based on studies suggesting that eating one meal a day can raise blood pressure and cholesterol, and it may cause blood sugar spikes.

Those effects could be risky for people with certain health conditions or anyone already struggling with their heart health.

If you are thinking about trying an OMAD diet, it is recommended to speak with a doctor first.

Healthline also warns it could cause side effects such as nausea, dizziness, irritability, low energy, and constipation, so it is not something to jump into without considering your health and lifestyle.