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Do Protein Shakes Make You Feel Full?
Yes, protein shakes can make you feel full, because protein is one of the most filling things you can eat or drink. A 2016 Purdue University meta-analysis confirmed that eating more protein increases feelings of fullness, at least in the short term (ScienceDaily).
But there’s a catch: a shake usually isn’t as filling as the same protein in solid food. You drink it in a minute, it’s mostly liquid, and many shakes are low in fiber. So how full a protein shake keeps you depends on how much protein it has, its calories, its thickness and fiber, and what you eat with it.
This guide explains what the research says, which shakes are more filling, and simple ways to make a protein shake keep you full longer.
What the Research Says About Protein and Fullness
In 2016, researchers led by Richard Mattes at Purdue University, with Heather Leidy at the University of Missouri, combined data from many studies on protein intake and fullness. The meta-analysis, published in the Journal of the Academy of Nutrition and Dietetics, found that:
- Higher protein intake increased feelings of fullness compared with lower protein intake.
- Larger protein loads had a bigger effect than smaller ones.
- Modestly higher protein may help people feel fuller between meals.
The authors were careful about the limits (ScienceDaily):
- The studies looked at short-term fullness, not long-term weight loss.
- They couldn’t say exactly how much protein, or at what time of day, is best.
- Many individual studies were small and used different methods.
- As Mattes put it, people eat for many reasons besides hunger, so protein isn’t a “magic bullet.”
What that means for you: a protein shake is a smart choice when you want something more satisfying than a sugary drink or snack. It won’t override hunger completely, but it helps.
Why Protein Shakes Are Less Filling Than Food
Even with the same protein, many people find a shake less satisfying than a meal. Feastgood’s review of satiety research points to several reasons (Feastgood):
| Factor | Why it matters | Shake vs food |
|---|---|---|
| Volume | A bigger volume stretches the stomach and signals fullness | Small shakes take up little space |
| Calories | More calories usually means more filling | Many shakes are 150 to 230 calories |
| Speed | Food you chew takes longer; fast-digesting drinks fill you less | You can drink a shake in a minute |
| Fiber | Fiber slows digestion and adds bulk | Most shakes have little fiber |
| Thickness | Thicker drinks tend to feel more filling | Thin shakes feel lighter |
| Protein amount | More protein, more fullness | Varies from 20 g to 42 g per bottle |
Factors summarized from Feastgood’s review of satiety studies, including work by Camps et al. (2016) on drink thickness.
Which Protein Shakes Are Most Filling?
Using those factors, here’s how some popular ready-to-drink shakes compare:
| Protein shake | Size | Protein | Calories | Fiber | Fullness factor |
|---|---|---|---|---|---|
| Core Power Elite 42g (Chocolate) | 14 oz | 42 g | 230 | 2 g | Highest protein, big bottle |
| Core Power 26g (Chocolate) | 14 oz | 26 g | 170 | 1 to 2 g | Good protein, big bottle |
| BOOST High Protein with Fiber | 8 oz | 20 g | 240 | yes (with fiber) | More calories and fiber, smaller bottle |
| fairlife Nutrition Plan (Chocolate) | 11.5 oz | 30 g | 150 | 1 g | High protein for few calories |
| Premier Protein (Chocolate) | 11.5 oz | 30 g | 160 | 3 g | Good protein, some fiber |
Sources: Giant (Core Power Elite), Albertsons (Core Power 26g), Walmart (BOOST High Protein), fairlife (Nutrition Plan), H-E-B (Premier Protein).
For the most fullness from one bottle, Core Power Elite 42g stands out: lots of protein in a big 14 oz bottle. For a filling mini-meal, BOOST High Protein with Fiber adds fiber and more calories. For fullness on a calorie budget, fairlife Nutrition Plan packs 30 g of protein into 150 calories.
Not sure how they compare overall? See our guide to the best protein drinks and the Core Power vs Core Power Elite comparison.
8 Ways to Make a Protein Shake Keep You Full Longer
- Choose more protein. A 30 to 42 g shake fills you more than a 15 to 20 g one, in line with the Purdue findings.
- Add fiber. Blend in a tablespoon of chia seeds, ground flaxseed or a few tablespoons of rolled oats.
- Make it thicker. Blend with ice, frozen banana or Greek yogurt. Thicker drinks tend to feel more filling.
- Make it bigger. Blend a ready-to-drink shake with ice and a cup of berries for more volume without many calories.
- Add a little healthy fat. A tablespoon of peanut butter slows digestion.
- Sip slowly. Take 10 to 15 minutes instead of downing it in one go.
- Pair it with food. A shake plus an apple, a handful of nuts or a slice of whole-grain toast is far more filling than the shake alone.
- Drink it at the right time. A shake as an afternoon snack can stop you arriving at dinner starving.
For recipes, see how to make protein shakes taste better; many of the same add-ins make a shake more filling too.
Can a Protein Shake Replace a Meal?
Sometimes, but most standard protein shakes aren’t designed to be full meals. A 170-calorie Core Power has plenty of protein but little fiber or carbohydrate. If you skip a meal now and then, a higher-protein, higher-calorie option like Core Power Elite (230 calories) or a nutritional drink like BOOST (240 calories with 27 vitamins and minerals) works better, especially with a piece of fruit. As a daily habit, real meals are still the better choice.
Do Protein Shakes Help With Weight Loss?
They can help indirectly. Feeling fuller can make it easier to eat less, and the Purdue team noted that modestly higher protein may help people feel fuller between meals. But they also stressed that their study looked at short-term fullness, not long-term weight loss (ScienceDaily). A shake only helps if it replaces something less filling, not if it’s added on top of your usual meals.
Why Do Some Protein Shakes Make You Feel Bloated?
Feeling too full after a shake is common. Causes include lactose (if you’re intolerant), thickeners like gums or carrageenan, sugar alcohols, or simply drinking a large shake too fast. Core Power is lactose-free, which helps many people. If a shake bloats you, try a smaller serving, sip it slowly, or switch brands. Read more about Core Power’s ingredients in is Core Power good for you?
A Sample Day: Using Shakes to Stay Full
Here’s how a protein shake can fit into a normal day to keep hunger in check, without replacing real meals:
| Time | What to have | Why it helps |
|---|---|---|
| Breakfast | Eggs or Greek yogurt with fruit | A protein-rich start |
| Mid-morning | Water or coffee | Staying hydrated through the day |
| Lunch | A balanced meal with protein, vegetables and whole grains | The main fullness meal |
| 3 to 4 p.m. | A Core Power 26g (170 calories, 26 g protein) plus an apple | Bridges the long gap to dinner, when snacking is most tempting |
| Dinner | A normal meal | You arrive hungry, not starving |
| After a workout | A shake if you trained and dinner is a while away | Protein for recovery and fullness |
The afternoon shake is often where people see the biggest difference. Swapping a vending-machine snack for a high-protein shake gives you more protein for your calories and may make it easier to eat a sensible dinner.
Liquid vs Blended: A Simple Trick
If a bottle drunk straight doesn’t keep you full, blend the same bottle with a cup of ice and half a cup of frozen berries. You get the same protein in a thicker, bigger drink that takes longer to finish, which ticks three of the fullness factors above (volume, thickness and speed) for very few extra calories.
FAQs
Do protein shakes fill you up?
Yes, protein is filling, and research shows more protein increases short-term fullness. A shake is usually less filling than the same protein in solid food, though.
How long does a protein shake keep you full?
It varies. A higher-protein, thicker shake with some fiber or a bit of food alongside will keep you full longer than a small, thin shake on its own.
Why am I still hungry after a protein shake?
Shakes are quick to drink, low in volume and often low in fiber and calories. Add fiber, make it thicker, sip it slowly or pair it with food.
Which is more filling, a protein shake or a protein bar?
Many people find chewing a bar more satisfying, but it depends on the protein, fiber and calories in each.
Is a 42g protein shake more filling than 26g?
Generally, yes. More protein tends to mean more fullness, and Core Power Elite 42g has 16 g more protein than the 26g version in the same size bottle.
Can protein shakes reduce cravings?
They can help by keeping you fuller between meals, especially in place of a sugary snack.
The Bottom Line
Protein shakes do make you feel full, because protein is highly satisfying, and research confirms more protein means more short-term fullness. A shake is still less filling than food, so pick one with plenty of protein, add fiber or thickness, sip it slowly and pair it with a little food when you need it to last.
Shop high-protein shakes at DrinkWorlds → Core Power 26g and Elite 42g 12-packs, plus BOOST nutritional drinks, with free US shipping on orders over $35.
