How many scoops of whey a day? Work it out from your weight

There is no single number of scoops that suits everyone, because it depends on your body weight and the protein you already get from food. Whey tops up what is missing; it does not replace food. Work it out in 3 steps.

Step 1: protein you need per day

The International Society of Sports Nutrition (ISSN) concludes that most people who exercise should get 1.4–2.0 g of protein per kg of body weight per day.

Protein per day = body weight (kg) × 1.4 to 2.0

Step 2: subtract protein from food

Work out how much protein your usual meals give you in a day. The gap is what whey can fill. The ISSN itself says people who exercise can get enough protein from whole foods; supplements are a practical way to make sure you get enough.

Step 3: turn it into scoops

Scoops = protein still missing ÷ protein per scoop on the label

Example

A 60 kg person who exercises needs 60 × 1.4 = 84 g to 60 × 2.0 = 120 g of protein a day. Say their food gives 70 g; they are short 14–50 g. If their whey gives 25 g of protein per scoop, that is about 0.5–2 scoops a day. The food and per-scoop numbers in this example are made up; use your own.

How much at a time?

The ISSN suggests about 0.25 g of protein per kg of body weight, or 20–40 g, per serving, every 3–4 hours. If you need several scoops, spread them across meals, as this advice suggests. For timing, read when to take whey.

Who should ask a doctor first

The U.S. National Kidney Foundation (NKF) says people with kidney disease who are not on dialysis should eat less protein, and the right amount depends on the person. The American Kidney Fund says adding protein without knowing your real needs can be harmful. If you have kidney disease or are unsure, ask a doctor or dietitian before starting whey, and always tell them what supplements you take, how much and how often.