This is one of the most common questions I get from clients. Yes, it’s 2022 and yes, most people do now understand the concept of a calorie deficit and the fact that a deficit is required to lose weight.
But a lot of people still don’t quite grasp that you can eat pretty much whatever you want (within reason) in a calorie deficit.
Yes, that means you can eat Pizza, chocolate, donuts, cakes, cheese, bacon, sweets as well as drinking wine, beer, and spirits and still lose weight.
Let me explain how this works.
WHAT IS A CALORIE DEFICIT?
A calorie deficit isn’t magic. Being in a calorie deficit means existing in a state where you’re eating fewer calories than you use on a daily basis. In order to lose weight, you need to be in this state over a significant period of time.
The amount of weight you lose will depend on the size of the deficit, and the length of time you’re in a deficit for.
One Kg of body weight is roughly equal to 7,700 calories (1lb is equal to around 3,500 calories)
So that means that if you’re in a 500 calorie deficit per day, it’ll take you roughly 15 days to lose 1kg.
On the other hand, if you’re in a 1,000 calorie deficit per day, it would take you roughly 8 days to lose 1kg.
If you stayed in that 1,000 calorie deficit for 16 days, you’d lose roughly 2kg, and if you stayed in for 24 days you’d lose roughly 3kg
This is the bottom line. If you are eating fewer calories than you use, you WILL lose weight. There are no two ways about it, The body needs calories to sustain itself, and if those calories aren’t available, the body will start cannibalizing its own resources (i.e. stored body fat) to sustain itself.
Many people will claim they ‘can’t’ lose weight because of certain medical conditions. While something like thyroid dysfunction can affect metabolic rate, the fact still remains they if they eat fewer calories than they use, they’ll lose weight.
This is the law of thermodynamics and NO ONE is exempt from it! Just think about it; if you were that would mean you could stop eating completely (forever) and survive… and we know that isn’t a possibility!
WHAT ABOUT OTHER DIETS?
So if it’s true that you only need to be in a calorie deficit and it doesn’t matter what you eat, then why are there so many crazy diets out there? I’m talking about
Well, the key thing to recognize with all these ‘diets’ is that they are methods, whereas a calorie deficit is a principle.
All of these diets are essentially different, creative ways to get you into a calorie deficit. There is nothing magical about cutting out carbs or eating after 6 that will miraculously result in weight loss, these diets just provide an easy-to-follow method to get into that all-important calorie deficit.
|Diet||How People Think It Works||How it Actually Works|
|Keto||Carbs make you fat, so cutting them out helps you lose weight||It creates a calorie deficit|
|IF (Intermittent Fasting)||Eating after 6pm makes you fat, so if you stop you’ll lose weight||It creates a calorie deficit|
|OMAD||Eating multiple times a day makes you fat, so if you only eat once you’ll lose weight||It creates a calorie deficit|
|Low Carb||Carbs make you fat, so if you limit them you’ll lose weight||It creates a calorie deficit|
|5:2 Diet||If you eat 500 calories twice a week magic happens and you lose weight||It creates a calorie deficit|
|Mediterranean Diet||If you eat super healthy food you’ll lose weight||It creates a calorie deficit|
|Cambridge Diet||If you only drink ‘weight loss shakes’ you’ll lose weight, obviously||It creates a calorie deficit|
|Atkins Diet||If you do a diet some old dude wrote a book about of course you’ll lose weight||It creates a calorie deficit|
While these diets may provide an ‘easy-to-follow’ method for getting into a calorie deficit, the disadvantage with all of them of course is that they are restrictive in one way or another.
While this may work in the short term, none of them are sustainable ways to diet; cutting carbs may help you lose some weight in the short term, but are you really going to never eat carbs ever again? Of course not.
This is why learning how to get into a calorie deficit really is the only way to diet successfully and sustainably.
CLEAN EATING VS IIFYM
Another debate that rages on and doesn’t seem to die is the whole ‘clean eating VS IIFYM’ debate.
‘Clean eating’ refers to the practice of only eating whole unprocessed foods. This means only eating single-ingredient foods such as vegetables, fruit, lean meat, grain and dairy. The purpose of this is to lose weight by only eating healthy foods.
Of course, we already know that the only way to lose weight is to create a calorie deficit, and eating only ‘healthy’ food doesn’t guarantee that. Yes, sticking to the types of foods listed above can make it more likely that you’ll be in a deficit, but it doesn’t guarantee it.
The other end of the debate is ‘IIFYM’ (If It Fits Your Macros’), this is the dieting method that dictates that anything goes, as long as you are hitting your macros (and therefore calories).
This diet glamorizes eating highly processed, high-calorie foods like ice cream, pop tarts and donuts (along with some whey protein powder) within the context of a calorie deficit to lose weight.
Of the two approaches, IIFYM is the one that will produce weight loss (assuming that the macro and calorie amounts being eaten are appropriate for weight loss) but both have significant disadvantages
On IIFYM you’ll probably feel pretty trash since you’ll be getting very little fiber and missing out on some important vitamins and minerals (that is of course if you decide to take the diet at face value and only eat junk).
Clean eating on the other hand may give you more energy and make you feel good (and be better for your overall health), but if you’re you’re not in a calorie deficit then the bottom line is, you won’t lose weight.
Of course, both these dieting methods have their drawbacks. This study on clean eating found that it has significant potential for harm when taken to extremes, including;
- Negative physical and mental health issues such as osteoporosis and depression
- Promoting extreme views such has vomiting one particular food or food group.
- It may mask preexisting eating disorders, making them seem normal since they’re under the guise of ‘clean eating’
This not only suggests that you can eat what you like in a calorie deficit, but rather, you should, given all of the disadvantages of a diet that outlaws particular foods.
SO HOW OFTEN CAN YOU EAT JUNK FOOD ON A CALORIE DEFICIT?
Before I get going on this bit, I need to clarify that, just like with ‘clean eating, there is NO objective, official definition of junk food. When I refer to ‘junk food’ I’m generally speaking about highly processed, calorie-dense foods (come on, you know what junk food is).
‘How often can I eat junk food and still lose weight or ‘when can I have a cheat meal‘ are questions I get all the time, and the answer is simple.
You can eat Junk Food as often as you like and have as many ‘cheat meals’ as you like, and still lose weight. This is of course only possible if you create a calorie deficit
And yes, that means if you wanted to, you could just eat Pizza every day and lose weight. Or chocolate, or beer.
This is all theoretical though, and while eating Pizza every day and losing weight may sound like a dream, it does lack an element of pragmatism. What the hell do I mean by that?
Well, imagine actually eating Pizza every day.
First of all, you’d probably feel pretty trash. Although Pizza is delicious at the time, the large volumes of cheese and dough can leave you feeling bloated.
Second, pizza is incredibly calorie-dense (it has lots of calories for not much food), which means that half a Pizza may eat up your entire daily calorie budget. Yes, you’re eating Pizza, but you aren’t able to eat anything else and still be in a calorie deficit.
This isn’t ideal if you want to do anything else than lay around on the sofa all day. If you do any of kind of exercise or sport (or want to start), half a Pizza a day isn’t going to fuel you properly.
Finally, Pizza is quite expensive, so if you’re eating it every day, it’s going to cost you a lot of money.
So with all that in mind, let’s look at some of the aspects we need to consider when trying to cram in as much ‘junk’ as possible into a calorie deficit.
Satiety just means how ‘full’ or ‘satisfied’ you are after eating.
Satiety is affected by a few different things including
- The total weight (volume) of the food you eat
- The fiber content of the food you eat
- The protein content of the food you eat
Both protein and fiber and generally more filling than other types of foods. This means including high protein foods in your diet like;
- Poultry (Chicken, Turkey, Duck)
- Red meat (Beef, Pork, Lamb)
- Fish (Salmon, Cod, Haddock)
- Dairy (Yogurt, Milk)
- Whey Protein
And high fiber foods like;
- Beans (Cannellini Beans, Kidney Beans)
The more of these types of foods you include in your diet, the fuller you’re going to feel. That means you have less drive to eat making it much easier and more realistic for you to stick to a calorie deficit long term.
Of course, typical junk foods are rarely made up by the study listed above. Junk foods are generally made up of things that are likely to make you feel less satisfied like white bread, cheese, oil, and fatty meat (yes, meat is satiating but fatty meat packs a lot more calories than lean meat).
So, the bottom line is that junk food generally isn’t that filling, as well as packing a ton of calories.
This is another important factor to consider when it comes to junk food.
Calorie density refers to the number of calories per gram in a specific food.
It’s important to have an awareness of the calorie density of what you’re eating (at least roughly) because if you eat too many calorie-dense foods, you’ll be taking in a lot of calories but very little volume/weight of food.
This will mean two things. Firstly, you get to eat less food each day (because calorie-dense foods will quickly eat into your calorie budget), and second, you’ll likely feel less full (meaning you’ll want to eat more).
Incidentally, calorie-dense foods generally don’t promote satiety, so you’re effectively taking a hit on two fronts if you eat them a lot (i.e. you’ll feel more hungry AND you’ll be taking in more calories).
Some examples of of calorie-dense foods are;
- High-Fat Cheeses (Cheddar, Brie)
- High Fat Milk and Cream
- Nut butter (Peanut Butter, Almond Butter)
So, while you CAN of course eat these foods in a calorie deficit and still be guaranteed to lose weight, the more of them you eat the more difficult the diet is going to be.
It’s also important to note that a lot of these foods are ‘hidden’ in typical examples of Junk Food, for example, the Thigh and Legs from KFC are fatty cuts of meat anyway, but they’re fried in a ton of oil which will massively inflate the calories.
So, to make your calorie deficit as easy to stick to as possible it’s best to avoid these foods, as well as avoiding foods that contain them in excessive amounts. You’re far better off sticking to low calorie-dense foods like fruit, veg, lean protein and starchy carbs
Junk food is expensive.
Here in the UK if you want a takeaway Pizza, you’re looking at around £15. If you were to eat Pizza every day that’s £105 a week or £420 a month. Just on Pizza.
You don’t need me to dispel the myth that ‘eating healthy is expensive. It’s not.
My grocery shopping costs around £100 per month and is packed full of fruit, veg, meat, yogurt, potatoes, rice pasta, noodles, soups and a bunch of other stuff I eat on a daily basis.
Yes I’ll buy some calorie-dense stuff too like chocolate and peanut butter, and yes I’ll have takeaways, but it’s generally once every 2 weeks, NOT multiple times per week.
Eating junk food on a regular basis will not only make you fat but poor as well.
WHEN DOES IT MATTER WHAT YOU EAT
While calories do definitely rule when it comes to weight loss, the macros don’t necessarily matter. I.e., it doesn’t really matter what ratio of protein carbs and fat you eat.
Having said that, there is one trump card you can play that will make the process of weight loss slightly easier, quicker, and more efficient.
That trump card is protein.
So why is protein so good for weight loss?
Well, first of all, it’s highly satiating (remember that word?), and second, it has a high ‘thermic effect’. What the hell is the thermic effect? Let me explain.
The ‘thermic effect of food’ or TEF refers to the number of calories the body uses digesting each macronutrient (protein, carbs and fat)
YES, you DO burn calories eating. But importantly, you burn more calories digesting protein than you do carbohydrates or fat.
How many I hear you ask? Let me show you.
|Macronutrient||% of Calories Burned in Digestion|
Yes, on average, 25% of the calories you eat from protein a used to digest it.
That means that if you ate 500 calories of White fish (which is pretty much 100% protein), you’d burn 125 of those calories digesting the food, so effectively, you’ve only absorbed 375 calories, rather than 500.
What all of this means is, you’ll find it much easier to be in a calorie deficit if you eat lots of protein.
But what about the other macronutrients?
Carbs are unfairly demonized in the media for being ‘bad’ for weight loss, and I really don’t know why
In fact, it’s worth calling out at this point that potatoes really are an unsung hero of the dieting world. Why?
Well, of all the foods tested in this study, potatoes rank highest in the satiety index, meaning they are technically the most filling food you can eat, yep more filling than protein!
There really is nothing inherently ‘bad’ about carbohydrates. It is true that you can see some rapid weight loss if you suddenly cut out carbs, but this is because carbs are stored in the muscles and liver in the form of glycogen. But this doesn’t mean you’re losing fat, and it won’t make you look any better.
People often wrongly identify carbs, and say they love carbs too much to lose weight, citing the problem foods as stuff like;
- Ice Cream
The thing is, these foods aren’t just carbs, they’re all made up of carbs and fat.
Chips (or Fries for our US friends) aren’t just sliced potatoes, they’re sliced potatoes cooked in a lot of oil. Oil contains a lot of fat and therefore a lot of calories, so when you’re eating chips you’re eating just as many calories from fat as you are from carbs.
Another example is bread, on its own bread is pretty much just carbs, but who eats just bread on its own? A Grilled Cheese (Cheese Toastie) isn’t just carbs, it’s carbs and fat. Same concept with Garlic Bread.
So, carbs are not a problem, and yes it doesn’t matter how many carbs you eat; as long as you’re in a calorie deficit, you’ll lose weight.
There is in fact an argument for eating more carbs than you do at the moment because of the high fiber content of the specific high carb foods. Fiber is generally found in bigger quantities in fruit, vegetables, beans, legumes, and oats.
This study on oats and their effect on satiety found that high fiber foods delay gastric emptying and reduce the rate of absorption of nutrients, which helps appetite regulation. This may mean that the more fiber you eat, the fewer calories you consume overall simply because your appetite will be lower.
Based on this, you could even argue that eating more carbs, especially high-fibre carbs, is good for sticking to a calorie deficit because it’ll help you adhere to it.
No one macronutrient needs to be demonized, and they all have a place in your diet, however, if you are going to limit one, it should be fat.
A gram of fat has over twice the amount of calories as a gram of protein or fat, check this out;
|Macronutrient||Calories per gram|
Yep, fat has 9 calories per gram, while protein and carbs only have 4.
This means that if you’re eating a high-fat food, you can pretty much guarantee that it’s going to be high in calories.
Examples of high-fat foods include;
- Fatty Meats
So, it’s best to limit these foods (or use lower fat alternatives) if you’re trying to lose weight.
Having said that, it doesn’t matter how much fat you are if you’re in a calorie deficit.
There is much debate about whether a low carb or low-fat diet is better for weight loss, and the debate will likely rage on for years, but the bottom line is that it really doesn’t matter, as long as you’re in a calorie deficit.
This study on 609 participants found that ‘ no significant difference in weight change between a healthy low-fat diet vs a healthy low-carbohydrate diet’.
I’ve already spoken at length about protein, and for the vast majority of people, having too much protein is not an issue.
In fact, 99% of the people I start working with ARE eating nowhere near enough protein.
Protein has a ton of benefits including;
- It’s satiating
- It helps to build and maintain muscle mass
- It has a high TEF (see above)
- It only has 4 calories per gram
All of these will help you lose fat, so there’s really no excuse for getting an adequate amount of protein in your diet.
Don’t believe me?
This study confirms that high protein (27%–35% of calories from protein) diets are indeed superior to ‘standard protein diets’ (16%–21% of calories from protein), referencing multiple clinical trials where participants on higher protein diets lost more weight and retain more lean body mass (muscle) than their peers on standard protein diets.
What’s an adequate amount?
I recommend that most people get at least 2g of protein per Kg of body weight. So if you weigh 80kg, that means eating 160g of protein per day. As long as you’re eating a portion of protein at each meal, this is actually relatively easy to achieve.
So, when it comes to protein it kind of does matter how much you eat (although it doesn’t matter if you’re in a calorie deficit), but in this case, more is usually better!
TIPS TO HELP YOU ADHERE TO A CALORIE DEFICIT
Of course, the only way to lose weight is to be in a calorie deficit, we know that.
We also know if are you are in a calorie deficit, it technically doesn’t matter what you eat.
Getting into a calorie deficit for a long period of time isn’t easy though, so you need to do everything you can in order to adhere to that deficit.
So from an adherence point of view, it kind of does matter. But even then, there are no strict guidelines.
The following works for most people, however;
- Prioritize low calorie-dense foods
- Limit (don’t cut out) high-calorie dense foods
- Get a portion of protein at each meal
- Get a portion of fruit of veg in at each meal
- Occasionally eat food you love. This is important. If you cut out things you enjoy (even if they are calorie dense) you’ll struggle to adhere to a diet, and adherence is the single most important thing
Here are a few other tips to help you stick to a calorie deficit
Caffeine has been shown to suppress hunger, it can therefore be used to help you stick to a calorie deficit.
Just make sure that you’re not guzzling down 400 calorie Starbucks Frappuccinos as this will totally undermine what you’re trying to achieve.
Stick to coffee or tea with a small amount of low-fat milk, caffeine gum or pills
There is no ‘ideal’ amount of times you should eat per day, and it doesn’t matter if you eat past 6pm.
Just ensure that you are eating at regular intervals, and try to eat at the same time each day. 3-5 meals per day is perfect for most people.
If you don’t eat for too long your hungry can become extreme, and that’s when you crave calorie-dense foods and can easily overeat.
As a last resort, there are weight loss drugs out there that can help you.
And no I’m not talking about magic pills that will melt away fat on their own. There are however several drugs out there that can help to suppress your appetite and reduce your drive to eat.
These drugs don’t automatically put you into a calorie deficit, they just help you adhere to a diet by aiming you less hungry, you STILL need to be in a calorie deficit.
Different drugs are available in different countries but Semaglutide (Wegovy) has recently been approved in the UK.
THE BOTTOM LINE
While it is true that it doesn’t matter what you eat as long as you’re in a calorie deficit (if weight loss is the goal), when it comes to actually achieving that deficit, adherence is everything.
Adherence is the ability to stick to that deficit long term, because if you can’t, then you won’t be in a deficit (or won’t be in a deficit for long enough) and won’t lose as much weight as you want.
The key to adhering to a deficit is to count calories, activity as well as track your bodyweight regularly, but also eating a balanced diet, probably with protein and vegetables than you are now, but also one that includes foods you love.
Is #cleaneating a healthy or harmful dietary strategy? Perceptions of clean eating and associations with disordered eating among young adults:
Clinical Evidence and Mechanisms of High-Protein Diet-Induced Weight Loss: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7539343/
Dietary fiber and satiety: the effects of oats on satiety:
Effect of Low-Fat vs Low-Carbohydrate Diet on 12-Month Weight Loss in Overweight Adults and the Association With Genotype Pattern or Insulin Secretion: https://jamanetwork.com/journals/jama/fullarticle/2673150
Joe is an online weight loss coach and qualified personal trainer of 15 years who helps busy, professional men and women lose fat and build muscle.
Having a 9-5 desk-job, Joe understands the struggles of juggling a hectic life with trying to maintain a good physique.