Best protein shakes for weight loss and metabolism boost

Written by Ro Huntriss, RD

Medically reviewed by Joanne Mainwaring

Published on July 29, 2025 | Updated on July 29, 2025

If you’ve ever stared at the protein shake aisle wondering whether you’re buying a diet-friendly superblend or just expensive chocolate milk, you’re not alone. The world of protein shakes can feel like trying to choose a movie on Netflix—so many options, but which one will hit the spot?

Let’s fix that. In this guide to the best protein shakes for weight loss, we’ll walk you through what actually works—backed by science, not social media—how to choose the right shake for your goals, and what to avoid unless you enjoy drinking disappointment.

What are protein shakes and how do they work?

Protein shakes are high-protein drinks typically made by mixing protein powder with water, milk, or milk alternatives, and often used for weight loss or muscle gain. Some come pre-mixed for convenience, while others let you DIY your blend. They’re designed to increase your protein intake—which plays a key role in building and maintaining muscle mass muscle mass The total amount of muscle tissue in the body, including skeletal muscles that contribute to strength, metabolism, and overall health. , managing appetite, and supporting metabolism metabolism The body's process of converting food into energy and maintaining vital functions, including breathing, blood circulation, and cell repair. .[1]

Now, here’s where things often get confused: 

High protein shakes are not designed for replacing full meals, even as part of a weight loss diet. While they can help curb hunger and contribute to muscle growth (because, well, they’re loaded with protein), they typically lack the full balance of calories, carbs, fats, and micronutrients that your body needs in a complete meal.

That’s where meal replacement shakes for weight loss come in. These are specifically formulated to replace a meal—often with added fiber, vitamins, minerals, and a more complete nutritional profile. They’re especially useful for helping people on lower calorie diets—but who don’t have much time for meal prep or planning—get all the necessary nutrients.[2, 3] 

So in short:

• Protein shake = supplement (workout recovery, smarter snacking)

• Meal replacement shake = stand-in meal (balanced nutrition, calorie-controlled)

Knowing the difference can help you avoid accidentally turning a snack into a not-so-filling dinner.

What are the benefits of protein shakes?

Protein shakes are supplements—they don’t replace whole food sources of protein, but they can play a supporting role by adding extra protein to your diet which can be helpful when you’re trying to manage weight or build muscle.

Here’s what protein shakes can do for you:

• Promote satiety: Protein helps you feel full for longer, which can curb cravings and reduce the urge to snack between meals.[1, 7, 8]
  

• Support muscle repair and growth: After exercise (or even just a hectic day), protein helps your muscles recover and rebuild, which is essential for preserving lean muscle mass muscle mass .[8, 9]

• Boost metabolism: Digesting protein requires more energy than carbs or fats, which gives it a slight thermic advantage (i.e., your body works harder and burns more calories processing it.[1, 8] This helps boost your metabolism metabolism naturally.

• Convenient nutrition: When time is tight, you need a quick, grab-and-go snack, or you’re racing back to the office after a lunchtime gym session, a well-made shake can fill the gap without blowing your diet.[2, 3] 

How do protein shakes help you lose weight?

Are protein shakes good for weight loss? They can be! 

How protein shakes work for weight loss is by helping you eat fewer calories without feeling like you’re constantly battling your body.

They do this by:

• Improving satiety: That concentrated protein source keeps hunger in check—especially if the shake is low in added sugars and high in fiber or healthy fats—so you’re less likely to snack impulsively or overeat later.[1, 7]
  

• Helping preserve lean muscle: When you lose weight, your body can burn both fat and muscle. Keeping your protein intake high supports muscle mass muscle mass maintenance—important, because more muscle means a higher resting metabolism metabolism .[10, 11]

• Making calorie control easier: Replacing a high-calorie snack with a protein shake can help reduce total calories.[2, 12]

• Supporting consistency: Having a quick, tasty, go-to option makes it easier to stick to your eating plan and avoid the cookie jar, even when life gets busy or you’re feeling frazzled.[2, 3, 12] 

Protein shakes don’t work for weight loss because they burn fat, but by helping set the stage for your body to do so more easily and effectively.

What are the best protein shakes for weight loss and muscle gain?

Before you worry about flavor, brand, or whether your blender leaks, you need to know what is the best kind of protein shake for weight loss and muscle gain for you. Different protein sources offer different perks—some digest faster, some keep you fuller longer, some are better for vegans, and some … well, just taste good.

Let’s break it down:

Whey is the most popular protein for a reason. It’s fast-digesting, rich in essential amino acids essential amino acids Nine amino acids that the body cannot produce and must be obtained from food sources. , and especially high in leucine, the MVP for muscle repair and fat loss.[9] Whey comes from milk, so it’s not vegan, but it’s ideal post-workout or as a snack to curb cravings.[9]

Perfect for: People who want results fast—literally. It gets to work quickly and has strong research behind it for both weight loss and muscle gain.[9] 

Casein is whey’s chill sibling. It’s also made from milk, but it digests slowly, releasing protein over several hours. That makes it great before bed or during long stretches without food.[13]

Perfect for: Fitness enthusiasts or intermittent fasters who want to keep their muscles fed overnight.[13] 

No dairy? No problem. Vegan protein shakes use pea, hemp, rice, chia, or blends of plant-based sources to provide a complete amino acid profile. They’re often higher in fiber, and many brands now rival whey in terms of texture and taste.

Perfect for: Vegans, vegetarians, the lactose-intolerant, and anyone who prefers their protein animal-free and compost-friendly.

Soy deserves its own spotlight. It’s one of the only plant proteins that’s naturally complete—meaning it contains all nine essential amino acids essential amino acids . It’s also low in fat, high in fiber, and high in polyunsaturated fat, as well as being rich in isoflavones, which may have additional health benefits for some.[14]

Perfect for: Anyone looking for a well-researched, high-quality plant protein with proven performance perks, including fat loss and maintaining muscle mass.[15] 

Made from—you guessed it—egg whites. It’s low in fat and carbs, high in protein, and digests at a medium pace. It’s especially good if you want dairy-free high protein shakes for weight loss without going fully plant-based.

Perfect for: Paleo-friendly folks and people who like their shakes dairy-free .

Pea protein is a standout in the vegan protein world. It’s rich in iron, relatively high in branched-chain amino acids (BCAAs), and surprisingly filling thanks to its high fiber content. Plus, it blends well and doesn’t have a chalky texture.[16] 

Perfect for: Vegans, vegetarians, or anyone looking for a gentle-on-the-gut, allergy-friendly protein source.

Hemp protein is made from ground hemp seeds, so it’s not just a protein source—it also brings in healthy omega-3 fats, fiber, and minerals.[17] It has a slightly nutty, earthy taste and a bit more texture than other powders.

Perfect for: Whole-food lovers, fiber fans, and people looking for added micronutrients in their shakes.

Pick a flavor you won’t dread daily

Here’s the real secret: the best protein shake for weight loss is the one you can drink without holding your nose and knocking it back. Because, let’s be honest: it doesn’t matter how nutritionally superior a protein shake is if it tastes like old socks. 

Choosing the right flavor is key to making this a habit you’ll actually stick with. Whether you’re a vanilla loyalist, a chocolate devotee, or someone who lives on the edge with salted caramel-cold brew-cookie fusion (yes, that’s real), go with what you genuinely enjoy. Life’s too short for sad shakes.

Try before you commit 

Thankfully, many brands offer sample packs or trial sizes—some even for free, others for just a few bucks. Use them! It’s the easiest way to taste-test different flavors, textures, and formulas before you commit to a giant tub that may otherwise become an expensive doorstop. Pro tip: test with the liquid you’ll actually use (e.g. water, almond milk, oat milk) to get a true sense of how it’ll fit into your daily routine.

What are some of the drawbacks and potential side effects of weight loss protein shakes?

One of your best allies on a weight loss journey can be a protein shake—but let’s keep it real: they’re tools, not magic potions. And, like any tool, they work best when used wisely. Here’s what to watch out for before you go all in.

Added sugars and sneaky sweeteners

Some shakes come dressed up like dessert—packed with sugar or stuffed with artificial sweeteners your body (and your goals) really don’t need. Flip that tub around and read the ingredients list before you blitz. If “candy bar” vibes outweigh the nutrition, it’s a red flag.

Bloating, gas, and digestive drama

Too much protein—especially from whey, soy, or sugar alcohols—can cause bloating, gassiness, or even constipation in some people. If your gut feels off after your shake, try drinking plenty of water, switching protein types, or easing into it with smaller servings. 

Nutrient imbalances

If shakes start replacing too many meals, you risk missing out on important nutrients, fiber, and the diversity of real food. Even the best meal replacement shakes aren’t a full-time substitute for veggies, grains, or healthy fats. Your body needs the whole spectrum—as well as the chance to chew!

Excess calories = unexpected weight gain

Not all protein shakes are low-cal. Some are packed with nut butters, oils, or added sugars to boost taste, which can easily send you over your calorie target—especially if you’re having multiple a day without adjusting the rest of your meals. Sneaky calories can add up fast, so always read the nutrition label.

Shake overload

Replacing every meal with a shake might sound efficient, but it gets boring and nutritionally lopsided. Whole foods offer more than just macros—they give you texture, satisfaction, and nutrients you just don’t get from a blender.

Taste bud fatigue

Even the most delicious chocolate fudge brownie flavor gets old if you’re drinking it every day. Switch it up with new flavors, add-ins like berries or nut butters, or a few well-chosen sample packs to avoid hitting the wall of shake boredom.

Kidney strain (if overused)

For most healthy adults, high-protein diets are safe. But if you have pre-existing kidney conditions, overdoing the protein—especially via supplements—can put added strain on your kidneys.[18] If that’s you, speak with your medical provider before adding shakes to your routine.

Allergic reactions

Some protein powders are made from common allergens like dairy, soy, or eggs. If you have allergies or intolerances, check labels closely. Reactions can range from mild bloating to full-blown immune responses—definitely not part of the plan.

Diabetes and prediabetes

Got diabetes or prediabetes? Talk with your doctor before adding protein shakes to your routine. Some can spike blood sugar or mess with medication timing, so it’s best to get the green light first.

Kids and teens

Protein shakes can have a place in a busy teen’s diet, but food should come first. If you’re thinking about giving them to a child or teenager, check in with a medical provider to make sure it’s the right call.

Pregnancy, breastfeeding, and preconception

Trying for a baby? Pregnant or breastfeeding? Your nutrient needs are a bit different right now, so chat with your midwife or doctor before reaching for the blender.

Tips on using protein shakes to lose weight

You’ve got your best protein drink. You’ve got your goals. Now how do you actually make it work for your weight loss plan and your life? Here’s how to get the most out of that blender bottle.

Choose high-quality ingredients

Start with the good stuff. Look for shakes with 20–30 grams of protein per serving, minimal added sugars, and a short list of ingredients. The best protein shakes to help you lose weight and build muscle usually don’t require a science degree to be understood.

Use shakes to complement, not replace, meals

Protein shakes are great sidekicks, but they’re not meant to take over your entire diet. Use them to fill gaps—a mid-morning pick-me-up, a post-workout boost, or a quick snack when things get hectic. 

If you’re trying to replace a meal, look for products specifically labeled as “meal replacements”—those are designed to include enough calories, fiber, healthy fats, and micronutrients to truly stand in for real food. And even then, limit it to 1–2 meals max per day, and only use them for short periods of time.

Pair shakes with a balanced diet

A protein shake is a helpful tool, not a hall pass to skip your veggies. Make sure the rest of your day includes a variety of whole foods: colorful fruits and veggies, healthy fats, whole grains, and fiber. Protein can’t do it all alone.

Drink shakes at the right time

There’s no one perfect time for a shake, but they often work best after workouts (to support muscle repair) [5, 6] or in the morning (when convenience matters most). The key? Fit it into your day in a way that helps you stick to your nutrition goals and your life.

Customize for more staying power

Plain protein powder is a blank canvas. Want to make it more filling? Add chia seeds, a spoon of nut butter, berries, a handful of spinach, or a sprinkle of oats. You’ll boost fiber, healthy fats, vitamins, and flavor too.

Choose lower-calorie shakes (when that’s the goal)

Some shakes sneak in extra calories through oils, creamers, and added sugars. Go for low calorie protein shakes that are lighter on sugar if you’re using them for weight loss, so you can stay full while hitting your nutrition goals on the nose.

Track your protein intake

To support fat loss and preserve lean muscle, aim for about 0.8 to 1.2 grams of protein per kilogram of body weight per day.[1] That might require a little math at first, but once you find your rhythm, it’ll get easier.

Stay hydrated

High protein intake can increase your need for water (especially if your shake is thick enough to double as pancake batter). Make sure you’re drinking plenty of fluids throughout the day to help with digestion, kidney health, and energy levels.

Frequently asked questions

How many protein shakes should I drink if I’m trying to lose weight?

If you’re curious about the best quantity of protein shakes for losing weight, most people do well with 1 shake per day. ideally fuelling a workout or supporting workout recovery. More than 2 per day may crowd out whole foods.

Can you lose belly fat by drinking protein shakes?

Not directly. No nutrition strategy or workout targets fat in one area, but increasing protein and reducing overall calories can help you lose body fat, including around the belly.

Why do I feel sleepy after a protein shake?

It could be due to a blood sugar dip (if the shake is too low in carbs), food sensitivity, or too large a serving. It could also be due to the effort it takes to digest the shake (blood gets diverted to the gut which can sometimes make people feel tired and lightheaded). Try adjusting the portion size, ingredients, or timing—maybe split it into two smaller servings and sip slowly.

Is it better to drink a protein shake before or after a workout?

Either works, depending on your goals and your schedule. After a workout is often ideal, especially for muscle repair and recovery.[5, 6] It also helps keep you full until your next meal.[1] But if it’s been a while since you’ve eaten, having a shake before your workout (ideally 30–40 mins before to allow for digestion) can give you an energy boost and help you perform better.[6] Bottom line: the best time is the one that fits your routine and helps you hit your nutrition targets.

Is it OK to drink 1 protein shake every day?

Yes—as long as it fits into your daily calorie, protein, and nutrition goals. Use it to supplement a balanced diet, not replace it entirely.

Written by Ro Huntriss, RD

Medically reviewed by Joanne Mainwaring

Published on July 29, 2025 | Updated on July 29, 2025