What’s the best protein powder for fat loss and muscle gain?
The same powder does both jobs. Pick the most protein for its calories: whey, or soy if you skip dairy. But in 49 trials, lifting built far more lean mass than the shake did.
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What is the best protein powder for weight loss and muscle gain?
The one that gives the most protein for the fewest calories. Muscle needs the protein, and fat loss needs fewer calories.
So one tub serves both goals.
Whey is the usual pick if you eat dairy.
A review of 9 trials looked at people lifting weights. Soy gave similar gains in strength and lean mass (muscle and other body parts that are not fat) to whey and other animal proteins. So pick by what you eat, then by the label.
Each gram of protein counts as 4 kcal on UK labels. Times the protein by 4 and compare it with the calories.
Source: Food labelling law (1169/2011)
Scoop B suits someone trying to gain weight. For fat loss and muscle at once, pick a tub like Scoop A.
Can you lose fat and gain muscle at the same time?
Yes, in one strict trial. Young men ate about 40% fewer calories than they needed for 4 weeks. They lifted weights and did hard interval training 6 days a week.
Half ate 1.2 g of protein per kg of body weight a day. Half ate 2.4 g. The higher-protein group gained more lean mass and lost more fat.
| Change | 1.2 g protein per kg | 2.4 g protein per kg |
|---|---|---|
| Lean mass | Up 0.1 kg | Up 1.2 kg |
| Fat | Down 3.5 kg | Down 4.8 kg |
| Fitness tests | Improved | Improved the same |
Source: Longland 2016
That trial changed the diet, not just a shake. And it was 20 young men per group, training far harder than most of us. The authors called it a proof of principle: a test of whether it can happen at all, not of what most people will get.
So it can happen. Copy the parts you can: a calorie cut, more protein and regular lifting.
Does the shake or the training build the muscle?
Mostly the training. A review pooled 49 trials of weight training.
Lifting alone added about 1.1 kg of lean mass over around 13 weeks. Protein supplements added about 0.3 kg on top.
Source: Morton 2018
That’s the lifting. The shake helps a little, and it helped less with age and more with training experience.
It matters when you diet too. In people with obesity losing weight, high protein helped keep lean mass but didn’t improve strength.
Weight training did improve strength. The authors advise enough protein, but not too much.
No plan yet? Start with a beginner gym plan, then add a little weight over time with progressive overload.
How much protein a day for fat loss and muscle gain?
The UK guide for adults is 0.75 g per kg of body weight a day. Most of us already eat more than that, the British Nutrition Foundation says.
Lifters need more. In the 49 trials, extra protein stopped adding muscle above about 1.6 g per kg. The authors say up to 2.2 g may be wise if you want the most gain.
- Below 0.8 g per kgBelow the UK guide for adults.
- 0.8 to just under 1.6 g per kgMeets the UK guide.
- 1.6 up to 2.4 g per kgElite athletes losing weight: 1.6 to 2.4 g.
- Above 2.4 g per kgAbove that range.
Sources: British Nutrition Foundation; Morton 2018; Hector 2018
The 1.6 to 2.4 g range is for elite athletes losing weight, not a UK guideline. How big the calorie cut is and how hard they train decide where they sit in it.
At 80 kg, 1.6 g per kg is 128 g a day. Count one normal day of food to see your gap. Our protein per day guide shows how.
How to use protein shakes for weight loss and muscle gain
Swap, don’t add. NICE says weight loss needs you to eat less energy than you use. A shake on top of your usual food adds calories.
Five steps to use a shake for both goals
- Do strength exercises that work all your major muscles on at least 2 days a week.
- Swap a shake for a snack or drink, so your day has fewer calories, not more.
- Aim for 20 to 40 g of a good-quality protein per shake, or 0.25 g for each kg you weigh.
- Times the protein on the label by 4 and compare it with the calories.
- Get most of your protein from food, and use a shake for the gap.
Sources: NHS; NICE; ISSN; British Nutrition Foundation
Busy and training hard? The British Nutrition Foundation says shakes may be a handy way to get enough, though food is better where you can.
To set a calorie cut, use our calorie deficit calculator. For ideas on what a shake can replace, see protein powder for weight loss.
When to speak to a GP
Speak to a GP if:
- You have kidney disease. People with kidney failure do better on less protein, and too much carries risks. Ask your kidney team or GP before you add a powder.
- You keep losing weight without changing your diet or exercise. Go as soon as possible if you also have other symptoms.
- You think you may have a food allergy, such as to milk or soya.
Call 999 for a serious allergic reaction, if:
- your lips, mouth, throat or tongue suddenly swell
- you’re breathing very fast or struggling to breathe
- your throat feels tight or you’re struggling to swallow
- your skin, tongue or lips turn blue, grey or pale
- you suddenly feel very confused, drowsy or dizzy
- someone faints and cannot be woken up
- a child is limp, floppy or not responding like they normally do
Want to know how your kidneys are doing? See our kidney function test guide.