When we think protein, we think muscle. And while this nutrient is crucial for repairing, maintaining, and building muscle, it also offers a long list of other important functions.
“Protein helps our body maintain fluid and pH balance, structures our hair and nails, and supports organ function,” says Pamela Nisevich-Bede, M.S., R.D., C.S.S.D., owner of Swim, Bike, Run, Eat! Sports Nutrition. Because we need protein for so many things, it’s crucial, especially for active people—who are constantly breaking down and rebuilding muscle—to get enough of it in our diet.
Here’s what else protein does for you:
- Helps produce antibodies that fight off infections
- Supports hormone production (think insulin and thyroid hormones)
- Keeps you feeling full and satisfied after meals
- Provides the building blocks for enzymes that run nearly every process in your body
- Helps maintain strong bones as you age
- Supports brain health and cognitive function
“The minute we get up and start moving around and sweating, our protein needs go up,” says Nisevich-Bede. So unless you’re sitting in bed all day, chances are you’re not getting too much of the stuff. In fact, Nisevich-Bede recommends most people—like frequent exercisers, those looking to lose weight or maintain a lean physique, and the middle-aged or older—aim to eat close to one gram of protein per pound of bodyweight per day.
That’s 190 grams per day for a 190-pound lifting junkie, and 120 grams per day for a 120-pound runner. FYI: A four-ounce serving of chicken breast packs about 34 grams.
Here’s a little reality check: The official government recommendation of 0.8 grams per kilogram of body weight (roughly 46 grams for women and 56 grams for men) is actually the minimum to prevent deficiency—not the amount for optimal health. And if you’re over 50, active, or trying to lose weight while keeping muscle, you likely need more.
Why Your Body Can’t “Save” Protein for Later
Here’s something most people don’t realize: unlike fat (which your body happily stores for a rainy day), your body can’t stockpile protein. You need to replenish it throughout every single day. That means skipping breakfast or going light on protein at lunch can leave you short—even if you crush a big steak at dinner.
Think of it like this: your body doesn’t have a special ‘protein storage’ tank—so you do better when you give it a steady supply. After you eat, your muscles respond for hours (not minutes), and exercise keeps that response elevated well beyond a tiny ‘window.’ Any extra amino acids your body doesn’t need right then may get used for energy, but the big win is still spreading your protein across the day.
That’s why spreading your protein across meals matters more than most people think. Loading up on 60 grams at dinner while eating toast for breakfast? Your muscles are missing out during those morning hours when they could be rebuilding.
If you’re consistently missing the mark on protein, your workouts will certainly be affected—but the negative impacts on your body don’t end there. Look out for these seven signs you’re not getting enough of this macro:
1. Your Workouts Have Been ‘Meh’
If you’re consistently feeling crummy in the gym or on runs, you may not be getting enough protein to support your efforts. “If your usual workouts feel more and more taxing and you’re not seeing results from intense exercise, the first thing you should do is look at your macronutrients,” says Nisevich-Bede.
According to a paper published in the Journal of the International Society of Sports Medicine, missing out on protein leaves the body without ample ability to build muscle, and with too little nitrogen, which can spur muscle breakdown, slow recovery, and tanking performance.
What This Actually Feels Like
You might notice:
- Weights that used to feel manageable now feel impossibly heavy
- Running paces that were comfortable six months ago now leave you gasping
- That “fired up” feeling you used to get from a good workout? Gone.
- You’re hitting plateaus that no amount of effort seems to break through
- Exercises that used to feel easy now leave you completely drained
The frustrating part is that you might be putting in more effort and getting less results. If that sounds familiar, your protein intake deserves a closer look.
A Quick Self-Check
Ask yourself: When was the last time you actually felt strong during a workout? If you can’t remember, and you’ve ruled out things like poor sleep or overtraining, low protein could be the missing piece. Many people don’t realize that their body needs extra protein on workout days—especially within a couple hours after exercising—to help muscles recover and grow.
2. You’re Constantly Sore
While it’s totally normal to be can’t-get-up sore after trying a new workout or cranking up the intensity, something is off if your usual ‘ole workout is leaving your muscles wrecked. “If you’re doing the same workout day in and day out, you should be adapting and shouldn’t be constantly sore,” says Nisevich-Bede.
Related: 4 Possible Reasons Why You’re Still Wrecked Days After A Workout
Soreness seems to be an indicator of the muscle breakdown that occurs during and after exercise, so feeling that pain all the time could mean you’re not getting the protein your muscles need to rebuild. Plus, protein is especially important for our recovery from exercise-related injuries, and falling short may even prolong or worsen those injuries, according to a review published in Sports Nutrition.
When Soreness Becomes a Red Flag
Normal post-workout soreness typically:
- Peaks 24-48 hours after exercise
- Fades within 3-4 days
- Happens when you try something new or go harder than usual
But if you’re sore for 5+ days after a routine workout, or you feel like you never fully recover between gym sessions, that’s your body waving a little white flag. It doesn’t have the raw materials (protein!) it needs to repair and rebuild.
What You Can Do Right Now
If you’re stuck in a cycle of constant soreness, try bumping up your protein intake—especially around your workouts. A protein shake within an hour or two after exercising can give your muscles the amino acids they need to start repairing. And don’t forget about the rest of the day—your muscles are recovering around the clock, not just right after you leave the gym.
3. You’re Losing Muscle Instead Of Fat
Muscle breakdown doesn’t only impact how sore you feel, but it can also wreak havoc on your physique. When you don’t eat enough protein and can’t recover from your workouts properly, you may start to lose muscle mass—without losing an ounce of fat, says Nisevich-Bede.
Related: 11 Ways You’re Sabotaging Your Metabolism
So though the scale might not change much, the proportion of your body weight that comes from fat is increasing. And since how much muscle you have affects how many calories your body needs, melting muscle is a recipe for a metabolism slowdown and potential weight-gain.
The Sneaky Cycle to Watch For
Here’s where it gets frustrating: research published in Nature found that moderately low protein diets can actually make you hungrier—leading to more eating, more fat storage, and less muscle. It’s like a double whammy. Your body:
- Burns through muscle for energy (because it’s not getting enough protein)
- Cranks up your appetite to try to get more protein
- Stores extra calories as fat instead of building lean tissue
This is especially important if you’re over 50, when muscle naturally starts declining—research shows we can lose 1-2% of muscle mass per year after this age. The good news? Getting enough protein can help slow or even reverse this process.
How to Tell If You’re Losing Muscle
Beyond the scale, watch for these clues:
- Your clothes fit looser in some spots but not others
- You look “softer” even though you haven’t gained weight
- Everyday tasks like carrying groceries feel harder than they used to
- Your grip strength isn’t what it used to be
If this sounds like you, focusing on protein—combined with some resistance training—can help you hold onto (and even build back) lean muscle.
4. You Feel Pooped All. The. Time.
Fatigue can be caused by a number of things, like dehydration or being low in iron—but if you feel wiped out all day long in addition to being sore and having lame workouts, inadequate protein is the likely culprit. “If you have that leaden leg feeling all the time, chances are your protein intake and overall recovery are lacking,” says Nisevich-Bede.
Beyond Just Feeling Tired
Low protein can affect your energy in several ways:
- Your body might break down muscle for fuel, leaving you physically drained
- Blood sugar can fluctuate more when meals lack adequate protein
- Your mood might take a hit too—protein provides building blocks for feel-good brain chemicals
- You may feel foggy or have trouble concentrating
If you’re dragging through afternoons despite getting decent sleep, try adding more protein to your breakfast and lunch before reaching for another coffee.
The Morning Protein Fix
Here’s a simple experiment: for one week, make sure you get at least 20-30 grams of protein at breakfast. That could be:
- Three eggs with some cheese
- Greek yogurt with nuts and seeds
- A protein smoothie with fruit
- Cottage cheese with berries
See if your energy holds steadier through the morning and into the afternoon. Many people notice a difference within just a few days.
5. Your Sweat Smells Like Ammonia
No, you’re not crazy! Windex-like sweat is a very real thing—and it means your body is burning through your muscles for fuel when it doesn’t have another fuel source, like glycogen (energy stored from carbs) or amino acids (the molecules that make up proteins) available, says Nisevich-Bede.
Having amino acids available during exercise helps keep muscle out of a catabolic state (a.k.a. breakdown-mode), according to research published in the International Journal of Sports Nutrition and Exercise Metabolism. So it’s no wonder why so many experts recommend your pre-workout fuel contains some protein.
Why This Happens
When your body runs low on its preferred fuel sources, it starts breaking down amino acids from muscle tissue. This process creates ammonia as a byproduct, which then gets released through your sweat. It’s basically your body’s way of saying “Hey, I need more fuel here!”
Quick Pre-Workout Protein Ideas
If you’re hitting the gym and want to protect your muscles:
- Greek yogurt with a handful of berries (15-20g protein)
- A small protein shake 30-60 minutes before your workout
- A couple hard-boiled eggs
- A protein bar you can eat on the go
- Turkey or chicken slices rolled up with cheese
Even 10-15 grams of protein before exercise can help keep your body from dipping into muscle stores for energy.
6. You’re Under The Weather—A Lot
You’ve definitely never blamed a cold on not eating enough eggs or chicken breast, but protein has a very real influence on your immune system because it supports your organs and produces antibodies, which fight off harmful substances. “When you can’t maintain organs or antibodies, you’re at a disadvantage and can’t fight off infection very easily,” says Nisevich-Bede.
Research has found that amino acids—especially arginine, glutamine, and cysteine—have a variety of immune functions, like activating T-cells, confirming that inadequate intake can increase our susceptibility to infectious disease. Yikes.
Signs Your Immune System Might Be Struggling
Pay attention if you’re experiencing:
- Catching every cold that goes around the office
- Minor cuts and scrapes that seem to take forever to heal
- Feeling run-down more often than your friends or family
- Getting sick more frequently than you did a year or two ago
- Infections that linger longer than they should
While protein isn’t a magic shield, making sure you’re getting enough gives your immune system the raw materials it needs to do its job.
Building a Stronger Defense
Beyond just upping your protein, focus on getting a variety of protein sources. Different proteins contain different amino acid profiles, so mixing things up—chicken one day, fish the next, beans and legumes another—helps ensure you’re getting all the amino acids your immune system needs.
7. Your Hair And Nails Have Looked Better
Super dry hair or brittle nails? Since the structures of your hair, skin, and nails are made up of protein, extreme cases of not-enough-protein can have a very visible impact, according to Nisevich-Bede. Just as the body struggles to maintain muscle mass without enough protein, it struggles to keep up with the constant protein needs of our hair, skin, and nails.
The amino acid cysteine is especially important because it provides rigidity to the protein keratin, which makes up your hair and nails, per research published in the Journal of Biochemistry.
Why Your Body Sacrifices Hair First
Here’s the thing: your body is smart. When protein is in short supply, it prioritizes the essentials—your heart, brain, and other vital organs. Hair, skin, and nails? They get bumped to the bottom of the list. That’s why these are often the first visible signs something is off, even before you notice fatigue or muscle loss.
Watch for:
- Hair that’s thinner than usual or shedding more in the shower
- Nails that break, peel, or have ridges
- Skin that looks dull, dry, or less elastic
- Hair that’s lost its shine or feels more brittle
- Nails that grow more slowly than they used to
The silver lining: these changes can often improve once you bump up your protein intake consistently for a few weeks.
What Healthy Hair and Nails Need
Beyond just eating more protein, make sure you’re getting complete proteins that contain all the essential amino acids. Eggs are a great choice since they contain biotin as well, which also supports hair and nail health. If you’re eating plant-based, combining different protein sources (like rice and beans) throughout the day helps ensure you’re covered.
How To Boost Your Protein Intake
If you’re falling way short on that one gram of protein per pound recommendation—and paying for it in and out of the gym—your first step to getting more of the good stuff is to look at your meals. “Make sure you’re getting lean proteins at breakfast, lunch, and dinner,” says Nisevich-Bede. While many women can get by with closer to 20 grams of protein at each meal, most guys should shoot for 30, she says.
Know Your Numbers by Age
Here’s something worth knowing: your protein needs actually increase as you get older. If you’re over 50, research suggests you may need closer to 1.0-1.2 grams per kilogram of body weight daily—that’s about 25-30% more than the standard recommendation. Why? As we age, our bodies become less efficient at using protein, so we need more of it to get the same muscle-building benefits.
Spread It Out Throughout the Day
Remember: your body can’t store protein, so front-loading it all at dinner doesn’t work as well as spreading it across your meals. Here’s a rough guide:
| Meal | Women’s Target | Men’s Target |
|---|---|---|
| Breakfast |
20-25g |
30g |
| Lunch | 20-25g | 30g |
| Dinner | 20-25g |
30g |
| Snacks |
10-15g |
15-20g |
We know breakfast is a toughie; Nisevich-Bede suggests incorporating eggs, Greek yogurt, or a smoothie with protein powder into your morning meal to make sure your protein intake is steady throughout the day.
High-Protein Foods to Stock Up On
Looking for easy wins? These foods pack a protein punch:
- Eggs: 6g per egg
- Greek yogurt: 15-20g per cup
- Chicken breast: 34g per 4 ounces
- Salmon: 25g per 4 ounces
- Cottage cheese: 14g per half cup
- Lentils: 18g per cooked cup
- Tofu: 20g per half block
- Lean beef: 24g per 3 ounces
- Chickpeas: 15g per cooked cup
And then come snacks, which are often more carb-y foods, like pretzels or fruit. To reach your daily needs, make sure even your in-between-meal eats contain some protein. Go for easy bites like half a turkey sandwich, a protein shake, or hummus with vegetables, Nisevich-Bede recommends.
Plant-Based? You’re Covered Too
If you’re vegetarian or vegan, don’t worry—you can absolutely hit your protein goals. The key is eating a variety of plant proteins throughout the day. While many plant proteins are lower in one or two essential amino acids, combining different sources across the day fills in the gaps, combining different sources fills in the gaps. Think rice with beans, hummus with whole grain pita, or peanut butter on whole wheat toast.
When Supplements Make Sense
Sometimes food alone makes hitting your protein goals tricky—especially if you’re:
- Always on the go with limited meal prep time
- Plant-based and finding it harder to hit targets
- Training intensely and needing quick post-workout fuel
- Over 50 and dealing with a smaller appetite
- Trying to lose weight while preserving muscle
- Recovering from an injury or illness
That’s where a quality protein powder or ready-to-drink shake can fill the gaps without requiring you to cook another meal.
Choosing the Right Protein for You
Not sure which type of protein powder to try? Here’s a quick breakdown:
- Whey protein: Fast-absorbing, great for post-workout, contains all essential amino acids
- Casein protein: Slow-release, good before bed or between meals
- Plant-based blends: Usually combine pea, rice, or hemp to create a complete protein profile—great for vegans or those with dairy sensitivities
If you’re still not sure how much of the macro you’re getting—or are having trouble hitting the mark—using a food-tracking app or meeting with a dietitian who can help you get there.
Pin this infographic and keep your protein intake on track:
Diggin’ What’s Good? For more essential health facts, tips, and inspiration, join our Facebook communities, Eating Healthy and Staying Fit, today!