What To Do When You Mess Up Your Diet, Why It Happens & How To Stop It

How To Stop Messing Up Your Diet

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FREE CHEAT SHEET: 7 Ways To Stop Messing Up Your Diet To Reach Your Goals Faster

I only ever send out 1 - 3 emails a week and most of the time it's just 1 which is the Lift Learn Grow newsletter. By joining this list you agree to recieve these emails and acknowledge that from time to time they may be promotional/sales in nature. Your data will never be shared, sold or given away.

We’ve all been there…

A small unintended calorie surplus turns into an all-out binge.

@@The next thing you know you’re staring down the barrel of an empty Pringles can, whilst your friend tries to stuff the pizza boxes into the bin and someone in the corner moans about how full they are.@@

The causes can be seemingly endless; a last-minute dinner arrangement, the ‘just one more biscuit’ fallacy, a miscalculation of your calories or just about 100 million other reasons.

However, the result is always the same, you eat over your calorie allowance, mayhem ensues, and you’re left in an unwanted calorie surplus not just for the day but for the whole damn week.

Is there was any way you could have stopped it from happening?

I’m here to tell you that there is, there is a way to stop a small bump into the road becoming a full-on dietary car crash.

However, you first need to understand why this happens.

Why Do You Mess Up Your Diet?

In my experience there is no single factor that causes you to overeat, it’s generally a multitude of factors that more often than not combine to create the perfect storm of eating too much and not giving a fuck (at least not in the moment).

Let’s start by looking at the factors that contribute to this perfect storm.


You know that your mood and decision making takes a knock when you’ve had a bad night’s sleep and are feeling tired, but did you also know that reduced sleep can influence how hungry you feel?

A study (1) found that “participants with short sleep had reduced leptin and elevated ghrelin [levels]” and concluded that “these differences in leptin and ghrelin are likely to increase appetite”.

FYI – Leptin decreases hunger whilst Ghrelin increases hunger.

Another study found that (2) sleep deprivation impaired the function of parts of the brain vital to decision making which could impair your ability to make informed decisions about which food to eat.

Hello, junk food!

Combine this state of increased hunger with one or more of the following factors and you can begin to see how a small slip up can become an all-out binge.

Shopping Hungry

It’s a universal saying, “don’t go shopping on an empty stomach!” but do you know why when you shop in a state of hunger you end up buying stuff you don’t need and sometimes don’t even want?

The responsible party for this phenomenon is Ghrelin (3), a hormone that stimulates hunger in your body particularly when dieting.

A 2011 study set out to try and measure this effect by recruiting a group of participants who were either injected with ghrelin or a saline solution before being set loose to bid (eBay style) on edible and non-edible items.

Whilst participants were engaged in this behaviour the researchers observed their brain activity using a fMRI machine.

They found that the participants given the Ghrelin were not only willing to pay more than the other participants for edible items but were less interested in the non-edible items, offering a lot less than the other group.

Given this link between hunger and a tendency towards poor food decisions, it’s no surprise that shopping when hungry often results in you eating over your calorie allowance either directly (you buy it and eat it) or indirectly (you stock your house with high-calorie foods you can’t resist when tired, bored, drunk, etc).

Speaking of being drunk, let’s look at the next factor.


Alcohol is often thought to be a big factor for weight gain with the belief often being it’s an all or nothing kind of scenario. However, whether it’ll screw up your diet is not so clear-cut.

The truth is whilst alcohol when consumed with food tends to lead to an…

“increase [in] food intake, (probably through enhancing the short-term rewarding effects of food)”

…alcohol itself is not necessarily the lead contributor to weight gain, with researchers giving more weight to an individual’s “personality and habitual beverages preferences.” (45)

@@What this means is that if you’re drinking low-calorie drinks in moderation and account for it in your daily calorie intake, then alcohol won’t cause weight gain.@@

What will cause weight gain is the junk food you eat when under the influence of alcohol.

Which makes perfect sense…alcohol isn’t exactly known for its positive effects on decision making and it’s these poor decisions you make when drunk that leads you to mess up your diet.

Remember alcohol suppresses fat oxidation which allows your body to store fat and carbohydrates more easily but the actual conversion of alcohol itself into fat is negligible if it happens at all.

For more on how to include alcohol in your diet, read this…

Stress & Willpower

Do you eat more when you’re happy or sad?

What about relaxed or stressed?

How about a tough day compared to a breezy one?

If you’re like the vast majority of other people, then you will have noticed a trend towards bad eating habits and over indulgence when feeling down or stressed.

Add to the mix a social event where you expected or pressured into behaving a certain way or eating certain things and 9 times out of 10 the diet is out of the window.

To understand why we need to look at the results of a fascinating study (6) that measured the factors determining whether or not a judge would grant criminals parole at their parole hearings.

If you’re like me you’d expect that when ruling the judge would consider a variety of factors when making their decision. However, after looking at over 1,000 rulings spanning a 10 month period the researchers found that one of the biggest influences on the judge’s decision was the time of day.

The judge was most likely to rule favourably first thing in the morning with the chance of a favourable ruling steadily declining towards zero as the hours passed.

The same thing would then happen after the judge’s lunch break, rulings would start out being favourable before the chances of a positive ruling again decreased as the hours passed by.

 Data from the study show the decline in favourable rulings over the day. Notice the spike after the judge had rested followed by a consistent decline all the way down to 0.

Data from the study show the decline in favourable rulings over the day. Notice the spike after the judge had rested followed by a consistent decline all the way down to 0.


The reason for this decline is due to what researcher’s term ‘decision fatigue’ which essentially means that the more decisions you have to make, the more difficult it becomes to make them.

So as the judge continued to examine complex case after complex case the stress and fatigue of difficult decision making continued to build up until it was easier to just say no than engage the necessary brain power to make an informed decision.

It’s comparable to doing a set of challenging squats in the gym. With each consecutive squat, the movement becomes more and more taxing until you can’t squat anymore and have to stop.

This also what happens in your life every day and is made worse when you have a particularly stressful or taxing day. When this happens, you’ll find it that much more difficult to say no to high-calorie foods and prevent yourself from messing up your diet.

Combine this with the research (7) that shows some people will eat more of both calorie dense and high-fat foods when feeling stressed compared to those who are not stressed and it’s easy to see how after a long day your you’ll default to doing whatever is easiest even if you know it’s not good for you.

Hunger & Restrictive Dieting

We touched on this in an earlier point on shopping when hungry, but it goes without saying that hunger regardless of where you are or what you’re doing increases the likelihood of overeating. To make things worse this effect is magnified if you’re also tired, drunk, dieting and/or fed up of eating a restrictive diet.

Which leads us nicely to my next point.

Your diet is not something you should be battling with, yet this is easily one of the most common reasons for people messing up. It’s the same old story of restrictive ‘clean’ eating during the week followed by the perceived ‘freedom’ of the weekend.

@@NEWS FLASH – if you need a break from your diet then you’re doing it wrong.@@

Cutting out food items or food groups entirely is almost never a good idea, particularly if you like these foods. It’s the age-old, ‘you want what you can’t have’ situation where the end of the work week signals that it’s time to relax and you inevitably unwind by having all the things you couldn’t have during the week.

@@If the diet you eat is a struggle for you to stick to, then it’s not right for you and you need to make a change.@@


The devil finds work for idle hands.

Those 7 words are probably the most apt description of what happens when you’re bored.

@@Except instead of some mythical red creature in a pit of fire torturing you for eternity, it’s your brain leading you into temptation and damning you to an eternity of mediocre results.@@

But what is it about being bored that causes you to eat? In a word, dopamine. Dopamine is a chemical in the brain responsible reward-motivated behaviour and is responsible for the good feeling we get when we accomplish a goal.

It has been found that eating can stimulate dopamine and the good feelings it provides. Perhaps unsurprisingly junk food, particularly foods high in sugar, fat and sodium are good at making you feel great.

This behaviour is backed by existing research (13) which shows that subjects who were bored ate more calories than those who weren’t, with additional research (14, 15) supporting this finding with results that indicated “that boredom markedly increases food consumption [in] both obese and normal [subjects].”

It’s no wonder you reach for that packet of Doritos, popcorn or biscuits when you feel bored. You’re almost hardwired to chase that dopamine high.

Estimating Calories

I’m sorry to be the one to tell you this but you’re just not as good at accurately estimating your calorie intake or calorie burn as you think you are.

What’s worse, it’s probably causing you to mess up your diet!

Research (8) shows that whilst those who are actively trying to change their weight are more successful that those who aren’t, everyone struggles to get it right, often underestimating the calorie content of their meals by up to 25% (9).

This can result in you eating up to 125 extra calories for every 500 you think you’re eating.

Think about it, if you eat a diet of 2,000 calories a day this could easily result in you eating 500 extra calories daily, and that right there is your calorie deficit dead and gone.

When it comes to exercise, research (10) shows that when estimating the number of calories burnt through exercise individuals overestimate the total by as much as 72%.

Which is absolutely staggering.

But not too surprising when you realise that research also shows (12);

“normal weight individuals overestimate EE [energy expenditure] during exercise by 3-4 folds [and], when asked to precisely compensate for exercise EE with food intake, the resulting energy intake is still 2 to 3 folds greater than the measured EE of exercise.”

Is it really any wonder that even when you’re sure you stick to your calculated calorie allowance that you still manage to mess up on your diet?

Chunk in any of the other factors listed here and you’re on track for disaster.

What should you do?

7 Ways To Stop Messing Up Your Diet

What follows are 7 things you can do to help stop you messing up with your diet. There’s no one right answer on this list but instead a collection of different methods you can use in conjunction with each other to get the best results for you.


Identify Your Triggers

If you want to stop yourself from overindulging and going over your calorie allowance you need to learn to recognise your triggers i.e. what is it that causes you to stray from the plan and turn a small hiccup into a blowout?

Keep a diary and note down all the times you feel tempted to eat something outside of your normal meal times. Make a note of;

  • What are you doing, are you engaged or bored?
  • How do you feel, happy, sad, excited or bored?
  • Is it a normal day, have you done more or less exercise than normal?

By tracking when you’re tempted to snack or indulge and how you feel at those times you can begin to find the patterns or situations which trigger you.

For example;

  • Maybe you realise it’s always after dinner when watching Netflix that you want to snack
  • It could be that it’s only when you’re with friends that you overindulge
  • Perhaps on the days you do or don’t exercise you eat more
  • Do you find you eat more when you're procrastinating on doing something you need to do?

It could be any number of things that set you off but once you know you can take steps to counteract your triggers. It could be something as simple as;

  • Drinking a big glass of water
  • Taking a walk to stretch your legs and clear your mind
  • Doing a task that engages you
  • Or it could be that being aware of your behaviour is enough to stop you

The point is, that without tracking your behaviour you won’t know what your triggers are or how to overcome them.


Keep Problem Foods Out The House

Sometimes it just boils down to this, if it’s not in the house you can’t eat it.

No matter how much you might want it or try to eat it, you can physically eat something that’s not there.

Now, if you’re one of those people who can have certain foods around without giving into temptation then power to you, but if you’re someone who finds themselves saying “just one more” and is referring to the packet and not the biscuit then it’s safe to say you should keep these foods out of the house.

This simple change can be the difference between overindulging and sticking to your diet. If you have trouble making this change then just ask yourself what you’d prefer a snack cupboard or six-pack…food for thought.

Additionally, by separating your home from the place where you treat yourself can help remove the association you have with being at home with snacking.


Viewing Calories As Weekly Instead Of Daily

Another strategy to help prevent you from messing up your diet is to view your calories as weekly instead of daily.

This change will give you a better perspective of how your daily decisions and calorie intake will stack up over the course a week and whether or not they will make a difference.

This is important for 2 reasons;

  1. Although your weight can vary widely on a daily basis, changes in body composition at a more fundamental level don’t happen that quickly, this understanding is important for the next point…
  2. A small or even large overindulgence on your diet on one day when viewed in relation to your weekly intake often won’t make a huge difference and it’s possible for you to remain in a calorie deficit for the week

Obviously, this is within reason, if you go crazy and consumed 1,000s more calories than you need then it will mess up your whole week, but if it’s a couple hundred calories on one day then it won’t make a difference in the long run.


Don’t Eat Beyond Your Projected Allowance

A small point here but something I’ve noticed myself doing and thought was worth mentioning.

When I say projected allowance, I’m referring to days where you know you’ll be burning more calories than average, for example; in my case, I used to play football every Monday and knew I’d be burning more calories than normal.

Therefore, on Monday’s I knew I could eat more calories as I’d need to replace the calories I’d be burning through playing football.

Usually, this would be no problem and particularly when in a calorie deficit I could enjoy a bit more freedom than normal to include the foods I liked.

However, there were a couple of times I’d run into trouble and throw my deficit out of whack. This would happen when I’d eat my extra calories and then football would be cancelled, I’d then find myself in a position where I’d eaten 400 – 600 calories more than I needed.

Depending on your diet set up this may or may not be a problem and as we looked at in the point before this one, when viewed as a weekly total it‘s not always a big problem but nonetheless, it’s something to be aware of.


Plan Ahead

This is particularly important for counteracting those times when willpower is low, hunger is high, and tiredness has set in.

By planning ahead i.e. shopping in advance, prepping meals for the week and keep trigger foods out of the house, means that when you’re not in a position to make ‘good’ decisions you don’t need to.

All the decisions will have already been made and you can just get on with doing what you need to do. You remove all the temptation to stray and make it easy to avoid binge eating.


Keep A Food Diary

Find you keep messing up but you’re not sure why, think you’re in a calorie deficit but somehow, you’re gaining weight?

Then it could be that you’re underestimating your calorie intake or overestimating your calorie burn, or both.

Sure, this isn’t messing up your diet in the wider sense of this article but none the less it’s keeping you stuck firmly at square one so let’s address.

The best way to overcome this problem is to keep a food diary every day for as long as you need to, to stop it happening. This means not only recording what you ate but how much of it too.

Another good practice is to make notes on how you felt when throughout the day and see how this corresponds to your eating habits.

As with the first point in this list, this can help you identify any recurring behaviour patterns and gain a deeper understanding as to why and where you might be messing up your diet.


Use A Nutrition Plan That Works For You

There is a lot of debate about which diet is best, but that’s a topic for a different article, the point here is that whatever method of eating that works best for you is the one you should use.

If you keep jumping from unrealistic juice diet to unsustainable celebrity fad you will ALWAYS regain any weight you’ve lost and then some.

@@Like a dog is not just for Christmas, fat loss is not just for summer.@@

If you really want to lose fat and keep it off without putting yourself through a continuous cycle of messing up your diet, gaining weight and starting again. You must find something that works for you.

A few criteria to keep in mind when choosing are;

  • It must be sustainable i.e. you have to be able to stick with it consistently
  • It has to be something that will not be detrimental to your health
  • It preferably should not exclude any food group or food item unless for medical reasons
  • It must allow you to have a social life i.e. dinner out with friends, drinks with colleagues or whatever ‘a social life’ may mean to you
  • It must be made up of 70 to 80% nutritious foods with the remaining 20 – 30% being used to include the foods you like

If you can find something that fits the above criteria you’re on the right track. However, even with the perfect diet setup, they’ll still be times where you mess up your diet for one reason for another.

When this happens it’s important you react in the right way to avoid further damage.

How To Bounce Back If You Mess Up Your Diet

In my opinion, there is one primary way to bounce back and your ability to do this is a good indicator of your likelihood to mess up again and a good determinant of the ultimate outcome of your diet.

The best way to react is to;

Not sweat it and get right back on track.

I know this might sound counterproductive at first but hear me out.

When you mess up on your diet the first thing you’re going to want to do is to make up for it somehow, for some it’s punishing yourself with exercise to earn back those calories and for others, it’s imposing a 24 hour fast to restore the balance.

Either way, you don’t want to do either of these things as it only serves to reinforce the feelings of guilt associated with messing up on your diet.

You see if you punish yourself every time you slip up then you are only reinforcing the idea that it was wrong, which in turn increases the misery and guilt you feel.

Instead, the trick is to carry on as normal, accept that you are only human and get back to the plan straight away.

No brutal exercise sessions, no 24-hour fasts or any other sort of self-imposed punishment.

@@Keep it simple, use the strategies above to identify why it happened and put systems in place to help you avoid it next time and then just get on with it.@@

Remember, no one is 100%, so cut yourself some slack, give yourself some credit for all the times you have been on track and move forward.

Summing Up

There lots of different reasons you might mess up on your diet ranging from tiredness and alcohol to stress, willpower and even boredom.

However, using any of the following 7 strategies you can help minimise the chances that you’ll mess up;

  • Identify your triggers
  • Keep problem foods out of the house
  • Viewing calories as weekly instead of daily
  • Don’t eat beyond your projected allowance
  • Plan ahead
  • Keep a food diary
  • Use a nutrition plan that works for you

Ultimately, it’s important to remember that we’re all prone to messing up our diet from time to time but it’s how you react that defines the outcome.  

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FREE CHEAT SHEET: 7 Ways To Stop Messing Up Your Diet To Reach Your Goals Faster

I only ever send out 1 - 3 emails a week and most of the time it's just 1 which is the Lift Learn Grow newsletter. By joining this list you agree to recieve these emails and acknowledge that from time to time they may be promotional/sales in nature. Your data will never be shared, sold or given away.