How Much Protein Is in a Chicken Breast?

Ask five websites how much protein is in a chicken breast and you will get five different answers. One says 25g, another says 31g, a third insists it is 54g. They are not all wrong. They are measuring different things, and the gap between them is exactly why this question is more confusing than it should be.

So here is a clear answer, in grams, for the way people in the UK actually buy and cook chicken. Then we will look at what changes the number, how much protein you really need, and why it matters more than usual when you are trying to lose weight.

How much protein is in a chicken breast?

For a skinless chicken breast, grilled or roasted, the reliable figure is about 32g of protein per 100g. That comes from the British Nutrition Foundation, drawing on the standard UK food composition tables, and it lines up closely with the US figure of roughly 31g per 100g.

A quick reference for cooked, skinless breast:

Those numbers are for cooked weight, which is the sensible way to think about it, because cooked is how you eat it. It is also the source of most of the confusion online, so it is worth understanding why.

Why raw and cooked numbers differ

Raw chicken breast is roughly two-thirds water. When you grill, roast or pan-fry it, a good chunk of that water evaporates and the breast shrinks, often by about a quarter of its weight. The protein does not go anywhere, so as the water leaves, the protein becomes more concentrated per 100g.

That is the whole trick behind the contradictory figures. Raw chicken breast comes in around 23g of protein per 100g. Cook it and the same meat lands near 32g per 100g. Neither is a mistake. They are just weighed at different moments.

Does how you cook it change the protein?

The protein in the meat itself barely changes with cooking method. What changes is everything around it. Grilling, roasting, poaching or air-frying a skinless breast keeps it lean, so your protein per 100g stays high and the calories stay low.

Frying in oil or butter adds fat and calories without adding protein, so the food becomes more calorie-dense even though the protein figure is similar. Breaded or battered chicken is the bigger shift: the coating adds carbohydrate and soaks up oil, which is why a breaded fillet can carry far more calories than a plain grilled one for a similar amount of protein. If you are counting, weigh and log the chicken as you cooked it, and account for any oil separately.

Protein by portion size

Most people do not eat exactly 100g, so here is what common portions actually deliver. These are cooked weights, skinless.

A note on that 100g protein search everyone does: no, 100g of chicken is not 100g of protein. To get 100g of protein from chicken breast alone you would need to eat around 300g of cooked meat, which is a large, filling portion. Spreading protein across the day tends to work better than trying to load it all into one meal.

Chicken breast compared with other proteins

Chicken breast is popular for good reason. It is high in protein, low in fat when you skip the skin, and easy to portion. But it is not uniquely high. Several everyday foods sit in the same range, and knowing that gives you more variety. The figures below are per 100g, again from the British Nutrition Foundation.

Chicken thigh, for what it is worth, has a little less protein and a bit more fat than breast, which many people prefer for flavour and moisture. The skin adds fat and calories without adding meaningful protein, so leaving it on is a taste decision rather than a protein one. If you want more ways to build meals around this, our guide on protein shakes for weight loss covers when a shake genuinely helps and when whole food is the better call.

Chicken breast vs thigh, and what the skin adds

Breast is the leanest cut, which is why it tops most protein charts. Chicken thigh has slightly less protein per 100g and a bit more fat, which plenty of people happily accept for the extra flavour and because it stays moist. Neither is wrong. They are different trade-offs.

The skin is mostly fat. Leaving it on adds calories and a little saturated fat, but almost no extra protein, so keeping or removing it is a taste and calorie decision rather than a protein one. For weight loss, skinless breast gives you the most protein for the fewest calories, which makes it a sensible default even though it is not the only good choice.

How much protein do you actually need?

The UK Reference Nutrient Intake for protein is 0.75g per kg of body weight per day, which works out at roughly 55g a day for an average man and 45g for an average woman, according to the British Nutrition Foundation. Most people in the UK already eat more than this. One 150g chicken breast covers most of a day's baseline on its own.

That baseline is set to prevent deficiency, though, not to help you build or keep muscle. People who train, and people who are actively losing weight, generally do better on more. Sports nutrition bodies commonly suggest somewhere between 1.2g and 2.0g per kg per day for active adults. For an 80kg person, that is around 96g to 160g of protein a day, a meaningful step up from the baseline.

The broader principle from the NHS is simple and worth repeating: get your protein from a range of foods rather than leaning entirely on one. The Eatwell Guide points to beans, pulses, fish, eggs and lean meat, and rotating between them gives you other nutrients chicken does not. If you want to work out your own numbers, our guide to calculating your BMR is a useful starting point for setting daily targets.

Is chicken breast good for weight loss?

For most people, yes, and protein is the reason. Protein is the most filling of the three macronutrients, so a meal built around chicken breast tends to keep you satisfied for longer on fewer calories. That matters, because hunger drives so much of what we eat, something we look at in our guide to appetite suppressants and in how to handle food noise.

At roughly 165 calories per 100g when cooked, chicken breast gives you a lot of protein for its calorie cost, which is what makes it such a dependable base for a weight-loss meal. It is also naturally low in fat once the skin is off, so most of the calories come from the protein itself.

Chicken breast is not a magic food, though, and eating more of it than you need will not speed anything up. It works best as the anchor of a balanced plate: a palm-sized portion of chicken, plenty of vegetables for fibre, and a sensible amount of a starchy carbohydrate like rice or a source of healthy fat such as avocado. Variety is what keeps a way of eating going, so it helps to rotate your proteins rather than eat chicken at every meal.

How to hit your protein target without counting every gram

You do not need a food scale forever. A few simple habits get most people where they need to be. Aim for a palm-sized portion of a protein food at each meal, with chicken breast one of the easiest to reach for. Spread it across the day rather than saving it all for dinner, since a steady supply suits your body better than one large hit. And mix your sources, because eggs, fish, dairy, beans and lentils each bring protein plus nutrients that chicken does not.

If you do want to track for a while, weigh your chicken at the same stage every time, raw or cooked, and use the matching figure from the tables above. A week or two of that usually teaches you what a portion looks like, and after that you can trust your eye.

Protein, weight loss and GLP-1 medications

This is where a plain chicken breast becomes surprisingly relevant. When you lose weight, some of what you lose is muscle, not just fat. That happens on any diet, and it happens on GLP-1 medicines like Mounjaro and Wegovy too. In the SURMOUNT-1 trial of tirzepatide, participants lost far more fat than lean tissue, but lean tissue still came down. Muscle is metabolically valuable, so protecting it is one of the smartest things you can do while losing weight.

Protein is the lever that does most of that protecting. Appetite often drops sharply on GLP-1 treatment, so meals get smaller, and it becomes easy to under-eat protein without noticing. A high-protein, satisfying food like chicken breast earns its place here precisely because it delivers a lot of protein for relatively few calories. Pair that with some resistance training and you hold on to more muscle. We go deeper on this in our guide to maintaining muscle while on GLP-1 medications, and on how to build sensible meals in the Mounjaro diet starter plan.

This article is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare professional before starting any treatment.