Over the last few years, the term “flexible diet” has become the buzzword in fitness.
A flexible diet is where you eat whatever you want and lose weight. There are no rules, you can eat what you like. There are no meal plans and you don’t have to eat anything you hate, on a flexible diet.
You can technically eat nothing but ice-cream and cake everyday and lose weight. However, I don’t recommend that, for reasons I’ll explain later.
How it works
It follows the principles of the 2nd law of thermodynamics. If you consume fewer calories than your body burns, you lose weight. This is not up for debate. If your body is not getting enough energy from food, it will eat itself to survive.
Once you’ve worked out your calorie goal, a protein goal is then worked out, this makes sure the majority of weight lost is fat, not muscle.
When it comes to weight gain or weight loss, your body doesn’t care WHAT food you eat. Your body only cares about HOW much you eat. This is why flexible dieting is so effective. Most people struggle with diets because they cut out their favourite foods. This usually leads to you craving your favourite food, then caving in and going overboard. When people still eat their favourite foods, they tend to lose more weight and keep it off. (1)
One study showed, people that who regularly ate bread every day, lost more weight and stuck with the diet longer, than those who didn’t eat bread. A lot of mainstream diets shun bread. But this study showed, including something delicious like bread every day, allowed people to stick with their diet. (2)
The bread inclusion in a low-calorie diet designed for weight loss favoured a better evolution of dietetic parameters and greater compliance with the diet with fewer dropouts(Loria-Kohen et al., 2012)
What flexible dieting tells us is; no matter how good a diet is. It is only effective, if the person doing it, can stick with it.
How to work out my calories
The easiest way to work out how many calories you burn a day, would to be a use a calorie calculator. Luckily I provide a calorie calculator below.
Enter your details below and it will give you a baseline to work off.
Quick note: This calculator will give you a good set of numbers to work off. But there is nothing wrong with going more aggressive with your deficit. For most people, I recommend taking your maintenance number and taking off 15-25% off.
Lets say you burn 2000 calories per day, that would mean aim for 1500-1700 calories per day.
What happens if you go over your calories one day?
Doesn’t matter. If you go over one day, you can go under the next day. Or you could eat to maintenance during the weekend and diet more aggressive during the week. This is effective as most people tend to ruin there diet on the weekends, so having more calories makes it easier to adhere.
So, what I recommend most of you do is this. Work out your calorie target, multiply it by 7, make it a weekly target. Then have higher days on the weekend and lower days on week days.
So, if you burn 2000 per day and want to eat 1500 per day. That’s 10,500 calories per week. You could have 2000 on the weekend and during the week have 1300. That would then average out to 1500 per day.
How to work out my protein
Take your body weight in Kilo’s and multiply it by 1.6.
That’s the number of grams you want to eat per day. If you want to eat more that’s fine. If you end up eating a little less, that’s nothing to worry about. Anything is better than nothing. The reason I recommend 1.6g, is because it’s shown to be the minimum amount needed to preserve muscle mass during a diet phase. (3)
Lets say you weigh 80kg, that would mean you’d want to aim for around 130g of protein per day.
How about if I have a lot of weight to lose?
Aim for 1.6g of protein per target bodyweight. If you weighed 140kg, perhaps aim for 130g of protein too. Otherwise, you’d be aiming for 225g a day, which would be needless as most of the bodyweight you want to lose is fat, not muscle.
I compiled a list of my favourite low calorie, high protein sources. If you can base your meals around these, you’ll be onto a winner.
- Skinless chicken breast
- Egg whites
- Fat-free Fage
- Whey protein
- Vegan protein powder
- Lean cut beef
- 5% Beef or Pork mince
- Pork loins
|Protein source||Calories per 30g of protein||Weight|
|Skinless chicken breast||141||118g|
|Whey protein pwoder||150||38.3g|
|Vegan protein powder||210||53.5g|
|Lean cut beef||202||100g|
|5% fat mince||151||128g|
Carbohydrates and fat
You might have heard of IIFYM (If it fits your macros). It’s a very similar premise to what I call flexible dieting.
It’s where you eat what you want. But you must hit your protein, carbohydrate and fat goal. For me, that’s overkill and not necessary for most people. Ironically, being that anal, makes flexible dieting a lot less flexible. I want you to do as little as possible and get the best results possible.
So, if you prefer eating more carbs and less fat (like me), do that. If you have a preference for foods higher in healthy fat and lower in carbs, do that. It’s totally up to you. Or you can mix and match.
How to track
What gets measured gets managedPeter Drucker
It’s a good idea to start tracking your intake when you start a flexible diet. The main reason people, can’t lose weight is that they eat more than they think. When you are measuring your intake properly, it’s a lot harder to lie to yourself. It has been shown that those who keep food diaries, do a better job of losing weight and keeping it off. (6,7,8)
Back in the day, you’d have used pen and paper or maybe a spreadsheet. Nowadays we can record our food on an app. I recommend Myfitnesspal.
As well as a tracking app, you’ll need some kitchen scales. Without scales, you’re not going to know how much of food you’ve eaten. It’s also an eye-opener when you realise how many calories worth of peanut butter you’ve been eating.
Tracking on Myfitnesspal is quite simple, for a lot of food and drinks, you can simply scan the barcode and it will input the data straight into the database.
Once input, you can see the calories, carbohydrate, fat and protein.
For foods that don’t come straight out of a package, you’ll need to weigh them with your scales. For instance, let’s say you have a protein shake for breakfast, you’d need to weigh the powder out.
Once it’s added it’ll be counted in your daily total. You can then rotate your phone and you can see how much protein you’ve had and how much more you need to reach your goal.
For foods, such as meat, which require cooking. I advise weighing raw. This will be more accurate, when it’s cooked it loses water, so will weigh less, therefore the new weight won’t be as accurate.
What I love most about following a flexible diet, is being able to fit in foods like Mcdonald’s and still lose weight. If you are eating 2000 calories per day, you see that a Mcdonald’s double cheeseburger will fit no problem. If you’re on lower calories, you may need to tweak the rest of your day. But it can be done.
What about independent restaurants, without calorie information?
This is a question I get a lot. Instead of taking your scales to a restaurant or only going places with calorie info (that would not be flexible), you’re going to have to estimate.
What I do is find a chain with similar food. So if you’re going out for pizza, I’d find the most similar Pizza Hut pizza and use that instead.
It won’t be 100% accurate, but it’ll be close. You can also overestimate. So if you have one slice, in-put 1.2 or 1.5 slices, that way you can play it safe.
When counting calories you’re NEVER going to be 100% accurate. That’s not the point. The point is, it provides structure to your diet. Like training wheels on a bike, it’s a tool to help, but not something you do for life.
Is a flexible diet healthy?
It’s as healthy as you make it to be. If you are getting in plenty of fruits and vegetables (at least 5 servings of 80g), whole grain fibre, oily fish, lean protein, healthy fats, with a little sprinkle of junk food each day, this diet is very healthy.
But, from experience this isn’t what most people do.
Problems with flexible dieting
- Too much flexibility – Some people are better off with some rigidity to start with. Without some rules in place, a lot of people will try to eat nothing but chocolate, ice cream and protein shakes.
- Lack of nourishment – I know some people won’t eat any fruit or vegetables because they’re seen as a “waste of calories”. To sustain good health and performance, you can’t skimp on fruit and veg.
- Dental issues – It’s easy to eat a lot of sugar when following a flexible diet. If sugar is fitted into your calorie allowance, then you will lose weight and that’s fine. But the British Nutrition Foundation recommends no more than 30g a day, so that’s what I would also recommend.
- Obsessiveness – As I mentioned earlier some people get obsessed over their numbers, or refuse to eat out where calories are not listed. That’s not flexible, that’s unhealthy. If you have any history of eating disorders, this is NOT for you.
- Tedious – Tracking will be tedious when you first start. Like anything, you need to overcome that hurdle and once you have done that, it becomes easy.
Build each meal around a lean protein and a couple of servings of fruit and veg, then play around from there. To make sure you’re getting enough nutrients, you could track fibre. You want to aim for 14g of fibre per 1000 calories.
If you don’t want to track vegetables. As that can be very tedious. Take 200-300 calories off your daily target. So if you’re aiming for 2000 calories, put 1800 into Myfitnesspal. Then eat as many vegetables as possible, which will usually account for 200-300 calories per day. But do track what you cook them in, so if you roast them in oil, the oil counts.
Benefits of flexible dieting
- Nothing is off-limits – You eat what you want and don’t eat what you don’t want to eat.
- More likely to keep the weight off – those that follow a follow a flexible diet are more likely to keep it off. Most people who lose weight gain it back, because they follow a strict unsustainable plan. But here you create your own plan.
- Easier psychologically – If you know you can eat some chocolate every day and still lose weight, you’re more likely to stick with your diet.
Once you get over the initial hurdle of tracking and are in the swing of things, you wont look back to any fad diet. Once you have a good understanding of calories, you can then transition out of tracking and thats where full flexible freedom comes in.
As you can see, you can have your cake and eat it. But only if the amount is suitable to your goals.
In an ideal world, we wouldn’t have access to all these tasty foods, however as we do, rather than fight against nature, let’s work with it.
Remember the goal is to be flexible, not obsessive. I’ve laid down how I’d do a flexible diet and what’s worked for my clients. However, there is no one right way and you’re more than welcome to tweak things to make them suit you.
The best diet is the one, you can stick with.
If you have any questions, don’t hesitate to ask.
Josh is a Registered Associate Nutritionist, with the Association for Nutrition (AFN). He completed his degree in Nutrition at the University of Roehampton in 2021. He passed with a First Class with Honours.
Josh is also a tutor for up-and-coming Personal Trainers, where he teaches a Level 4 Advanced Nutrition course. This is for Personal Trainers looking to upskill their nutrition knowledge. This is done at Norfolk Health & Fitness.