Whey's main strength is quality per gram. It's a complete milk protein, about 43% essential amino acids and 11% leucine, the amino acid that helps switch on muscle building. It also digests fast.

In short lab studies, whey raises muscle protein building more than soy or casein, likely because of its leucine. 25 grams of whey protein gives you about 2.7 grams of leucine. That lands inside the 700 to 3,000 mg per meal range the International Society of Sports Nutrition (ISSN) suggests.

Then there's the type. Whey protein isolate is filtered to 90% protein or more, with most of the lactose and fat removed. Concentrate is less filtered, so it usually carries more lactose.

Plant protein's big win is who can use it. Pea, rice and hemp powders have no milk protein and no lactose, so they fit vegans and anyone with a milk allergy. Milk is one of the nine major food allergens the FDA tracks.

Blends close most of the quality gap. Plant proteins tend to run low in lysine and methionine. Mixing plant proteins, such as pea with rice, can give you an amino acid profile close to animal protein. Swapping red and processed meat for beans and other plant foods may also lower heart disease risk, though that benefit comes from whole foods, not powder.

In the best-known trial of pea protein vs whey, muscle growth came out close. Researchers gave 161 young men 25 grams of pea protein, whey or a placebo twice a day through 12 weeks of arm training.

Biceps thickness grew 13.4% with pea, 15.3% with whey and 10.7% with placebo. The gap between groups was not statistically significant, and strength rose the same in all three. A pea protein maker funded it and employed three of its authors, so treat it as one useful trial.

Pea protein is about 30% essential amino acids, against 43% for whey. To match the leucine in 25 grams of whey, you'd need about 38 grams of pea protein. So use a bigger scoop or a pea and rice blend.

Is plant protein as good as whey? For most people who lift, it's close enough. A 2018 review of nine trials found soy built the same strength and lean mass as whey and other animal proteins.

Rice protein matched whey in an 8-week trial of 24 trained men taking 48 grams after workouts. The one caveat: a 2021 review of 16 trials found animal protein gave slightly more lean mass in adults under 50. The edge was about 0.4 kg, just under a pound, and strength gains didn't differ. Harvard's guide to protein shows how beans, nuts and other plant sources fit a healthy diet.

For both goals, your daily protein total matters more than its source. The ISSN position stand suggests 1.4 to 2.0 grams per kilogram a day for active people.

So how much protein to build muscle? A review of 49 trials found gains leveled off near 1.6 grams per kilogram, about 0.7 grams per pound. Here's how the main targets look for a 160 pound person:

• Adult minimum (0.8 g per kg): about 58 grams
• Active people (1.4 to 2.0 g per kg): about 100 to 145 grams
• Lifters in a calorie deficit (2.3 to 3.1 g per kg): about 165 to 225 grams

Spread it across the day, about 20 to 40 grams every 3 to 4 hours. If you're not sure what that looks like on a plate, here's what a high-protein diet means.

Whey protein for weight loss has some support. In a review of nine trials in adults with overweight or obesity, whey users lost a little more weight and body fat than the control groups. Those trials compared whey with a placebo or control, not with plant protein, so they show that whey helps, not that it beats plant.

If dairy truly bothers you, plant protein is the safer bet. If it's only lactose, whey isolate may work fine. Many people with lactose intolerance can have about 12 grams of lactose, the amount in a cup of milk, with mild or no symptoms.

A milk allergy is different: whey is milk protein, so skip it completely. For everyone else, bloating often comes from what's added. Check the label for these:

• Concentrate instead of isolate, if lactose is your trigger
• Sugar alcohols such as sorbitol, which cause gas and loose stools in larger doses
• Soy, if you're allergic to it

Taste is personal. Many people find pea and rice earthier than whey, and blending with fruit hides most of it.

A protein shake is a handy top-up, but meals should carry most of your protein. Powders are dietary supplements, and the FDA doesn't approve supplements before they're sold. Pick one with third-party testing on the label.

A protein smoothie works best when it adds real food. Fruit, Greek yogurt or milk turns a scoop into a snack. If you'd rather skip the blender, grab a protein smoothie from the cafe. Ask the team which protein goes in if you need it dairy-free. Rewardz members can trade 150 points for a free smoothie, where the cafe offers it.

We lean food first, and so does our take on supplements vs whole foods. Our Weekly Meal Plan comes in 5, 10, 15 or 21 meals, from $8.89 down to $7.19 a meal. Eating plant-based? Our cafes also carry vegetarian and vegan sandwiches and wraps.