Considering changing your diet and trying the One Meal a Day (OMAD) fast?
Well, so did I.
This article documents my experience with the approach in one of my 30-day challenges (spoiler: experiment failed – read on to discover why), accompanied by a daily diary of insights.
Let’s dive in, but first of all, if you’re unfamiliar with the term, let’s explain it…
What is OMAD?
OMAD or One Meal a Day, is a fasting method that, unsurprisingly, involves only eating once a day.
An extreme form of intermittent fasting, it allows a greater window between meals, frequently around 22 hours +
For a sexy audio/visual explanation of the differences between various types of fasting, check out this YouTube video:
One meal a day vs intermittent fasting
Intermittent fasting is a way of eating that increases your window between meals.
Generally, this involves not eating anything for a minimum of 16 hours, followed by a maximum 8-hour eating window.
In practice, many people skip a meal, either breakfaster or dinner, with part of the fasting period spanning sleep.
OMAD, in contrast, means only eating one meal a day instead of two.
However, in practical terms, it often involves extending the non-eating window to 22-23 hours and then consuming either a meal or various snacks in the remaining time.
Why I’m trying it
I’ve been intermittent fasting for one-two years now, encouraged by its supposed effectiveness in neutralising many modern health conditions and in particular, its anti-inflammatory effect.
As I have an autoimmune skin condition, this aspect was of particular interest.
Immediately I noticed an array of positive effects from skipping breakfast, both improving healthy feels and making my mornings super-efficient.
However, recently I’d experience a big dip in energy after lunch at 12pm, feeling lethargic and unmotivated.
This was generally accompanied by overthinking and decreased in work output.
As my mornings were great work-wise, I thought it would be interesting to extend my non-eating window and potentially sustain my productivity levels.
Note that I’m very active in terms of daily exercise, so unlike many adoptees aiming for weight loss, I’m simply testing it for potential emotional and energy benefits.
It seems like society is conditioned to preference three square three meals a day for good health.
But this seems like more marketing ploy than scientific fact.
Much like bacon for breakfast inspired modern advertising as we know it, our three meal a day mantra appears more beneficial for food companies fattening us up and pharmaceutical companies medicating us than it does for humans.
The fact is, we’re eating too much.
According to research, obesity is now killing three times as many people as malnutrition. That’s a sobering fact.
Intermittent fasting is supported by promising research,
“Evidence is accumulating that eating in a 6-hour period and fasting for 18 hours can trigger a metabolic switch from glucose-based to ketone-based energy, with increased stress resistance, increased longevity, and a decreased incidence of diseases, including cancer and obesity.”
Despite these positive indications, however, it seems that increasing that fasting window might not extend the positive results, with two studies indicating it could:
a) Increase blood sugar levels and ghrelin, a hormone that increases appetite
b) Increase blood pressure and cholesterol
It seems such research doesn’t deter hardcore OMADers who are often using it as a form of calorific constriction for weight loss.
OMAD research is still sparse, however, and despite the lack of promising evidence in comparison to a more forgiving intermittent fasting schedule, I’m still keen to give it a go.
The benefits of OMAD
Science aside, these were some of the benefits I anticipated with OMAD. Let’s start with the most obvious:
Only eating once a day, albeit over an extended 2-3 hour window means less meal prep, which means more time saved through the day.
Working from home, I’m always surprised by the time it takes for meal prep and eating.
Inevitably, when I was intermittent fasting, this would also be accompanied by some mindless scrolling through Reddit and YouTube, often outlasting my meal.
Without wanting to sound like a productivity robot, only eating one meal a day may recoup this time to channel into more conscious activities.
This is a big one, and often under-appreciated.
I feel that the best method to achieve mental clarity is simple living.
That means removing the extraneous, minimalism-style.
With less to worry about we can often calm our monkey minds effectively and refocus on what’s important.
Meal prep and washing up afterwards are such examples of friction.
This isn’t only related to time savings, but also just planning what we’ll eat/at what time etc.
When eating simply not on the agenda, that mental energy is liberated for other tasks.
Eating once a day should also save money.
I probably should have tracked this in the experiment, but hey ho.
Anyway, my gut feeling is that saving will be made, although perhaps not as much as you might think.
I was only eating lunch anyway, which was generally a pretty simple meal of eggs, rye bread and salad, including an intermittent avocado-shaped treat.
Obviously I’m saving on these costs, but then again, I’m consuming more in the evening than usual.
I’m also probably splurging on nicer ingredients to treat myself for my one meal.
How I’m doing it
Everyone adopting this eating schedule might have a different approach, some people choosing to use their eating window at breakfast or lunch.
Personally, I’ll to stick to eating dinner, which fits perfectly with my current morning routine.
It already seems natural not to eat breakfast.
Plus, I currently exercise in the morning, and this feels more feasible when I retain some fuel from the night before, rather than exercising while hungry later in the day.
Exercise also tends to be an appetite suppressant (for me at least), which I don’t want later in the day before I actually do want to eat.
Exercising in the morning is also a great way to begin the day, so I’m happy with this setup.
Obviously the fact that I’m doing this experiment to reclaim more energy and productive hours for afternoon work means that my evening meal is a reward, signalling that it’s time to power down and rest/digest for the evening.
This might contrast with my current tendency to allow my work to spill into the evening, meaning a poor delineation between work and leisure time.
The final compelling reason to eat in the evening is that this tends to be the most sociable time for food.
While it’s generally easy to skip breakfast and lunch (apart from brunch etc. on the weekend), most social events are organised in the evenings and for me, it’s the time when I want to down tools and hang out.
Identifying real hunger
Many of us are so conditioned by our current eating habits that it’s hard to know whether we’re genuinely hungry or eating out of habit.
You see, we all tend to consume as a distraction from discomfort or boredom.
I work from home and as soon as my attention wanes, I imagine a buttered up piece of banana bread calling my name.
I now know, through self-reflection and meditation, that it (unfortunately) isn’t because I’m hungry.
Dealing with discomfort
Humans struggle with change, especially concerning well-worn routines and habits.
This diet is no different and is accompanied by a degree of suffering and discomfort.
If you’re someone who’s unable to dissociate from your emotional impulses and reactions, it might be difficult to last for the duration of the non-eating window.
Concerns of loved ones
As soon as I started skipping breakfast, people thought I was weird.
It doesn’t matter that there’s plenty of evidence suggesting the benefits of intermittent fasting, as many people ignore facts in favour of their existing beliefs.
Likely they’re looking for that which confirms their thoughts and are unwilling to do the hard work of questioning their assumptions.
Well, OMAD is worse and trying to explain to people what you’re doing will likely be met with questions about whether you have an eating disorder.
Okay, so here’s my rather rough OMAD diary, complete with daily activities, thoughts and reflections.
You’ll notice this isn’t a rigorous scientific experiment as I haven’t taken any objective measures.
I’m not doing this for weight loss but rather energy and productivity, so I’ll be rating myself subjectively every day.
Pretty standard up to midday for a Saturday. I played tennis in the morning. Then the rest of the day was transformed compared to my usual post-lunch slump. I was filled with energy and absolutely buzzing. Meditated post-lunch and found doing this on an empty stomach provided an unusual level of focus. Used this time to do some work before going to a cafe to meet some friends. Socialising was fine didn’t feel hard talking on an empty stomach. Unsure if this was just a good day in general, because it was a Saturday (and everyone loves the weekend). Gives me confidence to continue with the experiment.
- Energy – 9/10
- Focus/Productivity – 8/10
- Emotional state – 9/10
Woke up motivated after yesterday’s experience. As usual, getting to midday was fine. Was then slightly hungry. Likely my Pavlovian response to the previous intermittent fasting routine. Again, had a very clear-headed afternoon, which is what the experiment was intended to discover. Meditated with the same intense focus. Didn’t do my normal morning exercise because Sunday is generally a rest day, but stretched and went for a walk. Out walking, I did feel quite hungry, so possibly not great for extended exercise later in the day, near the end of the fast. Really looking forward to 6pm. After a couple of snacks at 6pm, then had a massive dinner (at just after 7pm) to get enough fuel on board, followed by grapes and dark chocolate. Felt a bit sick afterwards and then uncomfortably full through the night and into the morning. It’s going to be important not to eat too much too late and allow for digestion before bed.
- Energy – 5/10
- Focus/Productivity – 7/10
- Emotional state – 7/10
Didn’t sleep much and was awake/dosing early at 3am. Got up feeling full from the night before, and noticed minimal tension in my stomach when I started exercising. Did an hour in the gym and felt great, with a surplus of energy – 30-minute weights and 30-minute treadmill. Felt better as the day progressed. Deadline at work so had a full day of work and put in a real shift. Struggled in the early afternoon but then got into the zone mid-late afternoon and powered through, getting everything done. Started eating at 6pm. I’ve identified a problem with the two-hour eating window, however, in that it’s just not enough time to consume enough food before bed. It feels like a race against the clock to fill up without getting bloated. On this evidence, I think I’ll eat the same amount, but extend my eating window from two to three hours, meaning I eat from 5-8pm. That extra hour will likely be more sustainable in terms of lifestyle, meaning I’m not rushing and can graze/digest my food better before bed.
- Energy – 7/10
- Focus/Productivity – 7.5/10
- Emotional state – 8/10.
Again woke up really early. The fast might well be affecting my sleep. Stretched and did one hour’s cardio in the gym. Work was a bit hit and miss today. Did struggle with concentration during a boring afternoon task but improved from 3-5pm. Increased my eating window from 5-8pm today. Had some Muesli with banana and raisins at 5pm and went for a walk. Then spagbol, fruit and dark chocolate for dessert.
- Energy 7.5
- Focus/productivity 6
- Emotional state – 6.5.
Woke up feeling tired and in a funk. Thought I wasn’t going to go to the gym today, but plucked up the motivation and did a decent weights workout. Did more pull-ups today than usual. Perked up as the day went on and was pretty active, walking a lot and going shopping in the afternoon. I did struggle with motivation as the day wore on, especially when writing an article. Was definitely getting hungry towards the end of the day and was happy when 5pm rolled around.
- Energy – 6
- Focus/productivity – 6
- Emotional state – 4
Went to bed really early last night and slept well, although woke up feeling incredibly tired, with sore muscles from yesterday’s workout. Did some stretching, got to work and went to the gym for a cardio session. Overall, energy was okay until the afternoon and by then I was hungry for an hour or two before it was replaced by a serene feeling of calm and clarity. These are the perfect conditions for meditation. Still experienced problems with work focus in the afternoon, but perhaps that’s more due to the work itself rather than the emotional state. Come 5pm I was, unsurprisingly, hungry again. My worry is that with my high levels of exercise, squeezing all the nutrition needed into the available time frame is tough. If I was trying to lose weight or not exercising as much, it might be fine.
- Energy – 7
- Focus/productivity – 7
- Emotional state – 7
Slept well and woke up feeling refreshed. Didn’t work out today, as I noticed soreness in various muscles groups. It’s Friday, so another work day. Seemed to be struggling with productivity and getting down to work. Also felt low for some reason, which worsened as the day wore on. Went to work in coffee shops later in the afternoon and definitely hit a higher level of output. Again, 5pm swung around and felt relieved to be eating again. Ate a lot tonight as a reward for the week.
- Energy 6
- Focus/productivity – 6
- Emotional state – 4
Early end to the experiment
Although I normally go in for 30-day challenges, I decided to end this experiment earlier than usual as I just didn’t experience enough benefit to justify continuing.
The downsides could have been temporary blips and short-lived.
However, as I’m happy with my current intermittent fasting regimen (which is backed by compelling research), I didn’t feel it was worth persisting, especially as I wasn’t willing to adjust my activity and exercise levels to accommodate the fast.
Also as I was sampling the diet to improve afternoon focus, I didn’t feel such sacrifices in mood and energy were justified.
This test did allow me to re-evaluate my psychological dependence on food as I learned that I can endure a day without food, which was confidence-building.
However, it also made me realise how much joy I derive from eating and that there are probably better ways to optimise my afternoon productivity above such drastic dietary overhauls.
Moving forward I might try tweaking my eating window from 8 to 7 or 6 hours in line with emerging evidence and to test my optimal routine.
In the future, I may test again and fulfilling the usual 30-day challenge, but in any case, I hope you’ve found this introductory article enlightening.
If you’re looking to take responsibility for your diet and do a similar experiment, do your due diligence and consult relevant medical professionals as required.
- You can save time in meal prep and washing dishing
- You save money on food
- It helps you understand your psychological dependency on food
- There’s a tendency to feel very lucid in the afternoon
- Potentially beneficial to kick-start weight loss if that’s your goal, before transitioning to a more sustainable regimen
- OMAD appears to have less health benefits than more tolerant forms of intermittent fasting, according to research
- It’s hard to eat enough in a two to three-hour window without feeling sick and going to bed bloated, although this could be mitigated by eating at lunch instead
- It feels like a race to eat enough in your window, which can be stressful
- If you love food, like me, you lose some of the enjoyment of eating
- If you do a lot of exercise, you could feel low on energy
- Psychologically, you might feel a bit low – this would ideally be tested over a longer interval as it could normalise or be attributable to other factors
- You can get many of the benefits of OMAD through intermittent fasting, which in my mind is more enjoyable and sustainable
There’s plenty of information (and misinformation) online about OMAD and fasting in general.
For opinions from people practising this approach, check out the r/omad subreddit.