Athletes are always seeking the edge, whether it is a faster sprint, a stronger lift, or a leaner physique. Lately, many are turning to intermittent fasting, particularly the OMAD Diet (One Meal A Day), in the hopes of reaping performance and physique.
Can limiting yourself to one meal a day support your energy needs and recovery as an athlete? Here is the catch: it might not be as performance-friendly as you think. As an athlete, you need consistent fuel throughout the day to maximize training, recovery, and overall performance.
Let’s dive in and explore what OMAD is and why it might not be good for you.
Table of Contents
What is OMAD: The “One Meal Wonder”?
OMAD stands for One Meal A Day. It is a form of time-restricted feeding (TRF).
- Fasting Window: 23 hours
- Feeding Window: 1 hour
- Calorie Intake: Varies based on your personal goals
The one meal can be breakfast, lunch, or dinner, totally your choice. That’s it. You get only one shot to fuel or recover. This is not like skipping a meal. It is a full-on strategy that pushes your limits.
Intermittent fasting: OMAD’s Bigger Family
Before we zoom in on OMAD, let’s look at other common forms of intermittent fasting you might have heard of.
Intermittent calorie restriction (ICR)
- Fasting for >24 hours, 2-3 times per week
- Calorie intake on fasting days: 400-600 kcal
- Regular diet on non-fasting days
- Variations: 2:5 (2 days fasting, 5 days normal eating) and 3:4 (3 days fasting, 4 days normal eating)
Alternate day fasting (ADF)
- Fasting on alternate days
- Fasting day intake: ~500 kcal
- Normal eating on non-fasting days
Time-restricted feeding (TRF)
Daily fasting with fixed eating windows:
- 16/8 (16 h fasting, 8 h eating)
- 18/6 (18 h fasting, 6 h eating)
- 20/4 (20 h fasting, 4 h eating)
What happens when you fast?
Let’s say you have decided to fast as a way to quickly lose 8 kg for your competition next month. But do you know what happens to your body when you fast?
Let me tell you what’s happening inside your body when you are fasting.
- Fall in blood glucose: When you don’t eat food for a short time (8-10 h), your blood glucose will go down to a modest level, but you can still bring it back to normal by eating carbohydrates.
- Glycogen breakdown: Now, when you don’t eat food, even when your blood glucose falls, your body will start using up whatever glucose is there in your blood. There is no glucose left in the blood, but your body needs it for energy. So, what happens is glycogen (storage form of glucose) in the liver will start breaking down into glucose to continue supplying glucose (the main energy source for the brain) to the brain and the muscles to help you continue the exercise without crashing down.
- Fat oxidation: When glycogen also depletes, which it will eventually if you won’t eat, the body will start using fat (free fatty acids and ketones) for energy.
- Protein breakdown: Your body uses protein for energy when you eat very few calories (40-50% of the calories you need in a day) or you fast for a looooong time.
The buzz behind OMAD: Why is it so popular?
Let’s be honest, everyone likes shortcuts. And while OMAD is not exactly easy, for many people, it feels easier than counting calories, eating healthy, resisting cravings, or exercising every day. So, why is OMAD blowing up right now? Here is what is fuelling the hype:
- No more “what should I eat?” stress: Planning three to six meals a day can be exhausting, as you might feel tired after your busy schedule. OMAD? You eat once, and you are done.
- Celebrity glow-up stories: Some celebrity athlete swears by OMAD, and suddenly, it is trending. If it worked for him, it must work for me, too, right?
- Influencers flaunting fast results: You scroll past pictures with captions like: “Lost 10 kg in 4 weeks thanks to OMAD!” and it’s tempting, especially when you are stuck on the same weight for months even after putting all your efforts.
- Quick weight loss: People love the idea of big results with minimal effort. OMAD might help you with this.
While it is a simple approach, with no complicated meal planning and fewer kitchen hours, it is also an extreme method that pushes the boundaries of your nutrition and performance.
Just because it is trending does not mean it is ideal for you.
What’s Missing in One Meal?
The OMAD diet has gained popularity for its simplicity and potential weight loss benefits. But eating just one meal a day comes with its own set of challenges.
With limited time and space on your plate, there is often a lack of variety of food, making it hard to meet your requirements. Packing enough calories and essential nutrients into a single sitting can be surprisingly challenging, and you might feel under-fueled even after eating.
OMAD Benefits: The Bright Side
With all the buzz surrounding OMAD, it is easy to see why athletes and fitness enthusiasts might be curious. OMAD is marketed as a simple way to lose weight rapidly. But before you jump in, let’s take a closer look at what science says about its potential benefits.
1. Weight Loss
One of the main reasons OMAD grabs attention is its built-in calorie restriction; after all, it’s hard to overeat when you are only eating for one hour a day. Naturally, this can lead to weight loss, but what does the research say?
A study that combined alternate-day fasting (ADF) with endurance training showed a reduction in body weight. Another study done on normal-weight and overweight individuals following ADF also reported reductions in body weight.
On the contrary, a study involving healthy young men with Time-restricted feeding (TRF) (20 h fast and 4 h eating window) found no significant change in body weight.
2. Fat Loss
As I’ve mentioned earlier, when you fast, your body starts burning fat for fuel after all glycogen is used up, and that could be one of the key reasons people turn to OMAD to lose fat.
In one study, combining alternate-day fasting (ADF) with endurance training led to a reduction in fat mass. One more study conducted on resistance-trained male athletes following time-restricted feeding (TRF) with an 8-hour eating window also showed a decrease in fat mass.
Key Takeaway: While fasting can support fat loss, a consistent supply of fuel is key for your performance.
OMAD for Athletes: 10 Reasons to Think Twice
OMAD might promise quick wins, but it could come at the cost of your performance, recovery, and long-term health. Despite a few potential benefits, OMAD might present several significant drawbacks.
1. Low energy availability
Athletes need a steady supply of energy to fuel their training, and the more intense the workout, the higher the demand. Trying to squeeze all those calories into just one meal a day is a serious challenge.
Over time, this can lead to chronic energy deficit, known as low energy availability. This low energy availability can hurt your hormones, mood, sleep, and performance.
2. Depleted glycogen stores
For athletes, especially those pushing through high-intensity training, glycogen is your go-to fuel source when blood glucose levels fall. But when you are fasting for 23 hours straight, glycogen is likely to be depleted. The result? Fatigue sets in, and your performance starts to slip.
3. Muscle Loss
Protein is not just important, it is non-negotiable for athletes aiming to build or maintain muscle. Ideally, it should be spread across meals throughout the day to support muscle repair, recovery, and growth. But with OMAD, cramming all your protein into one meal becomes a serious uphill battle.
When your body goes for long periods without fuel, it may turn to protein for energy, which puts your lean mass, basically “muscles”, at risk.
Some studies showed no change in muscle mass. However, other studies found different results. In one study, rugby players showed reduced plasma protein levels by the end of Ramadan fasting, while in another study, ADF combined with endurance exercise led to a decrease in fat-free mass (muscle mass).
Key Takeaway: OMAD may save time and provide quick results, but it could also cost you the muscle you have worked so hard to build.
4. Recovery
After a training session, your body needs nutrition to repair muscles and replenish glycogen. While following OMAD, you might miss the suggested eating window of 30-90 minutes post-training, leading to impaired recovery.
5. Performance
When you don’t fuel your body adequately throughout the day, your performance is bound to take a hit.
Several studies looking at Ramadan fasting highlight this concern. One study noted a small but significant drop in endurance running performance.
Another observed a notable decline in the distance covered during the Yo-Yo level 1 test among male professional soccer players, particularly in the evening sessions. Athletes were also found to favour low training intensity and reduced tactical training.
In one study, researchers found a significant decrease in running distance by the second week of Ramadan fasting; however, by the fourth week, their performance returned to or even surpassed the baseline levels. Other research reported reduced aerobic capacity, speed endurance, and jumping performance in soccer players during Ramadan fasting.
While one study did show a slight improvement in endurance performance, others found no noticeable change in judo and football athletes during Ramadan fasting.
Key Takeaway: The evidence is mixed, but it can be concluded that fasting for long hours can impair athletic performance, particularly endurance and high-intensity sports.
6. Cognitive function
Training is not just physical; athletes also need mental clarity to execute strategies and make quick decisions. Prolonged fasting, however, can impair cognitive performance, leading to reduced focus, increased irritability, and mental fatigue during training.
One study assessing male athletes during Ramadan found that their cognitive performance in tasks requiring quick, sustained responses was stronger in the morning but declined noticeably in the late afternoon, particularly in areas like verbal learning and memory.
Key Takeaway: Always remember, when you are under-fueled, your brain suffers as well, not just your muscles.
7. Hunger strikes back
Ever finish a fast and feel like eating everything in sight? Extended fasting can leave you feeling excessively hungry, which may lead to overeating once you finally break your fast.
A study compared the effects of eating one meal per day to three meals a day with no calorie restriction. Participants in the one-meal group lost fat but also experienced a notable increase in hunger levels.
In another study, researchers also found an increased tendency among athletes to consume calorie-rich diets and energy-dense drinks after breaking the fast.
8. Nutrient Deficiencies
Consuming a limited variety and amount of food might lead to inadequate intake of vitamins and minerals, resulting in deficiencies. While carbohydrates and fats fuel your body with energy, and proteins support muscle growth and repair, vitamins and minerals play a crucial role in helping these nutrients do their jobs effectively.
Without adequate levels of vitamins and minerals, your overall performance can suffer.
9. Digestive Issues
Eating a large, calorie-dense meal in one sitting can put a strain on your digestive system. You might experience bloating, indigestion, and sluggishness.
10. Unsustainable in the Long Term
Eating only one meal a day might be difficult to follow for your whole life, and once you stop following OMAD, you might end up gaining weight more than you lost.
The Science Says Mixed Signals
Researches show mixed results. While some studies highlight potential benefits, others report no effect. Certain studies have observed declines in muscle mass and athletic performance.
Many current studies focus on general populations or religious fasting patterns such as Ramadan. Some don’t even account for changes in body composition. More high-quality, controlled studies involving elite athletes are needed.
Strategies to lose weight safely
Do you know you can lose those extra kilograms without resorting to extreme diets like OMAD? Here are some safer, performance-friendly alternatives for you:
- Eat 3-6 meals per day, depending on training demands.
- Control your food portions.
- Consume a balanced diet (whole grains, lean proteins, healthy fats, fruits, and vegetables).
- Avoid processed foods like fast food, baked goods, sugary cereals, soda, and chips.
- Stay hydrated.
- Consult a sports nutritionist to fine-tune your plan based on your goals.
Explore my posts to know how to portion your food: “How To Portion Your Food To Get 30 Grams Of Carbohydrates” and “Know How To Get 10 Grams Of Protein From Foods“
Final thought
The OMAD diet may offer simplicity and potential weight loss, but it also has drawbacks, especially for athletes. The physical demands of training, competition, and recovery demand more strategic and sustained nutrition than OMAD typically allows.
While trying OMAD might seem appealing for short-term goals, it is important to carefully consider its pros and cons, just like you would weigh your options before making a strategic move in a game.
You need fuel before, during, and after workouts. And while weight loss is tempting, it should never come at the expense of your health and performance. There is no scientific evidence yet to support OMAD for weight loss.
Personally, as a sports nutritionist, I would not suggest following the OMAD diet for weight loss.
Do not fall for trends. Your body and your performance deserve better.
References
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- Bhutani, S., Klempel, M.C., Kroeger, C.M., Trepanowski, J.F., & Varady, K.A. (2013). Alternate Day Fasting and Endurance Exercise Combine to Reduce Body Weight and Favorably Alter Plasma Lipids in Obese Humans. Obesity (Silver Spring). (pp. 1370-9). doi: 10.1002/oby.20353.
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Time to wrap up
What is your take on OMAD for athletes- a miracle or mayhem? Have you tried it yourself? Drop your thoughts in the comments below👇. I’d love to hear your experiences or ask me a question.