I Slashed My Protein Intake by 90 Grams (And Still Gained Muscle)
A natural bodybuilder’s year-long experiment
By: Jeremy Fox CNC, CPT
Updated: December 13, 2024
For fifteen years, I followed the conventional wisdom that you need at least one gram of protein per pound of body weight to build muscle.
This idea likely gained traction in the 1970s and 80s during the rise of larger-than-life bodybuilding icons like Arnold Schwarzenegger. In fact, I first read about the 1 g/lb protein requirement in Arnold’s Encyclopedia of Bodybuilding.
As a young aspiring bodybuilder, I held onto this golden rule of protein intake tighter than a deadlift bar on a PR attempt.
My copy of Arnold’s “Encyclopedia” with the gram per pound protein rule highlighted.
While the gram-per-pound ideology has dominated the fitness world for decades, it’s based more on assumptions and tradition than hard scientific evidence.
When I started studying protein requirements to become a Certified Nutrition Coach, I began to question whether an ultra-high protein diet was truly necessary — or even optimal for building my physique.
As a personal experiment, I reduced my protein intake from 240 grams to 150 grams daily at an average body weight of 172 lbs.
According to my long-held belief, I should have lost mass like a snowman in July. But that’s not what happened.
I’ve been eating less protein for almost a year, and the outcome has been eye-opening.
Now, I’m sharing the results of my experiment to help you understand how much protein you need to support your fitness goals.
If you’d rather watch and listen, my YouTube video has you covered. Click HERE to subscribe, or click on the button below!
The Experiment: Reducing Protein Intake
After years of meticulously tracking macros, my protein intake ranged from 1.2 to 1.6 g/lb. I even went as high as 2 g/lb at one point because more is better, right?
Not necessarily. A 2018 meta-analysis showed that protein intake above 0.74 g/lb did not lead to greater gains in muscle mass or strength.
For those uninitiated to scientific studies, a meta-analysis is the highest level of evidence you can get. This compelling data convinced me to embark on an experiment to significantly reduce my protein intake.
My new lower protein target was 0.8 g/lb.
The Decision to Cut Back
The decision to drop my protein intake didn’t come lightly. As a “hardgainer,” the idea of eating less protein raised a lot of fears:
- Would I lose muscle mass?
- Would my performance in the gym suffer?
- Would I feel less satiated or lack energy?
However, the more I read about protein utilization, the more comfortable I felt. And that I might be better off reallocating those calories to energy sources that fuel my training.
Adjusting My Diet
Cutting back on protein meant rethinking my entire approach to meal planning and rearranging macronutrient ratios to fit my new goals.
Below are my macro targets before and during the experiment. The percentages are my average targets with daily ranges in grams.
Macros Before Experiment:
- 40% carbs (230–380 grams)
- 25% fat (70–100 grams)
- 35% protein (230–270 grams)
Screenshot from MyFitnessPal showing my typical macronutrient ratios at the higher protein intake (2023).
Macros During Experiment:
- 55% carbs (300–450 grams) ↗️
- 23% fat (60–90 grams) ➡️
- 22% protein (130–170 grams) ↘️
As you can see, I mainly increased my carbohydrate intake to replace the calories from reduced protein. Yet my macros remained within the ranges recommended by the Dietary Guidelines for Americans 2020–2025.
Screenshot from MyFitnessPal showing my typical macronutrient ratios at the lower protein intake (2024). Note: The blue “Goal” percentages only allow increments of 5% in the free version.
Controlling Inputs
I aimed to control other variables in my diet and workout routine as much as possible. This approach would make it easier to notice any effects of lower protein intake.
Here’s what stayed pretty much the same during the experiment.
- Resistance training: I continued lifting weights 6 days a week for 40–60 minutes with similar intensity and training volume (tracked with workout journal).
- Recovery: I kept my nightly sleep schedule consistent while monitoring stress and recovery metrics (tracked with Oura ring).
Oura Ring app screenshots show my average sleep duration and heart rate variability (HRV) by month. I aimed to get 8 hours of sleep every night. My HRV varied as my body balanced stress and recovery.
Of course, not much stays the same for an entire year. My bodybuilding goals generally vary with the seasons, and I transitioned from lean bulking to gradual cutting in the spring.
Here’s what changed during the experiment.
- Calorie Intake: I eventually reduced my calorie intake from about 2,900 to 2,700 calories a day (tracked with MyFitnessPal).
- Cardio: I also ramped up my cardio workouts from virtually none to about 150 minutes a week during the fat loss phase (tracked with Apple Watch).
- Energy Balance: My daily energy balance shifted from a 5–10% surplus to a 10–15% deficit (tracked with spreadsheet).
This last point is essential because muscle gain generally requires a calorie surplus.
Screenshot of my average daily exercise minutes (including resistance training and cardio) from Apple Fitness. You can see the step change from April to May when I started doing more cardio for the cutting phase.
Measuring Outputs
I recorded my progress in notebooks and spreadsheets to see if there were any changes in muscle mass or strength.
These are the outputs I measured.
- Body weight: I weighed myself first thing in the morning most days (tracked with spreadsheet).
- Body composition: I measured lean mass and body fat using skinfold calipers about once a week (tracked with spreadsheet).
- Strength: I recorded all my workout sets, reps, and weights lifted (tracked with notebook).
Screenshot of the spreadsheet where I recorded my weekly average weight, body composition, and diet information.
It may seem overkill, but tracking all these metrics was essential to quantify the results of my experiment.
The Results: Muscle Mass and Strength Level
When I started this process, I wasn’t planning on sharing it online a year later. So, I didn’t take progress pictures right away.
However, I did document my physique starting when I transitioned to the fat-loss phase. Below are the before and after pictures from April to October.
This is my 6-month progress while eating 150 grams of protein daily with a small calorie deficit. I definitely didn’t waste away at 0.8 g/lb protein intake.
Throughout this journey, I also reviewed the data to determine if lowering my protein intake had any negative effects. And I’ve compiled a year’s worth of tracking to share the results.
I know not everyone likes to geek out on data, so here’s the key takeaway.
TL;DR: I did not lose muscle or strength. In fact, I actually gained muscle until deep into the cutting phase.
For my fellow fitness nerds, let’s dive into the detailed numbers and results.
Body Composition
The screenshot below shows my nutrition and body composition numbers for the entire year of the protein intake experiment.
Screenshot of my progress tracking spreadsheet showing actual average protein intake, calorie balance, and resulting changes in body composition.
Next, I broke this data down into seasons and bodybuilding goals to provide some additional context and help you make sense of it all.
- Lean Bulk Phase (Winter): In January, I switched from 1.4 g/lb to 0.8 g/lb but continued eating in a slight calorie surplus. As a result, I gained two pounds of lean mass by April, along with one pound of body fat. This proved to me that losing muscle should not be an issue with the lower protein target.
- Cutting Phase (Spring/Summer): I transitioned to a cutting phase in April by eating in a slight calorie deficit. Surprisingly, I maintained all my muscle mass while losing five pounds of pure body fat by September.
- Recomposition Phase (Fall): I went on an elk hunting expedition in late September, where I was in a massive calorie deficit for a week. This shows up in October’s numbers as a loss of three pounds of lean mass. That’s when I bumped up the calories slightly and switched to a recomposition phase (near maintenance calories). Since then, I’ve regained one pound of lean mass while losing two more pounds of body fat.
I took this picture of my brother as we followed the elk sign in the Colorado Rockies. Trekking up and down these mountains with minimal calorie intake resulted in the only significant muscle loss during this protein intake experiment.
I should point out that this year wasn’t about building as much muscle as possible. Instead, my goal was to maintain muscle while gradually burning body fat.
If I were doing a more aggressive bulking phase, it’s possible more protein may have been advantageous.
Strength Level
To see if my strength was affected, I reviewed my workout log for my heaviest sets on squats and bench press. I also included my maximum pull-up reps.
Here’s how my strength changed throughout one year of eating less protein.
Bulking Phase (Winter):
- Squats — 275 lbs x 6 reps
- Bench Press — 225 lbs x 5 reps
- Pull-Ups — 12 reps
Cutting Phase (Spring/Summer):
- Squats — 265 lbs x 6 reps
- Bench Press — 235 lbs x 6 reps
- Pull-Ups — 13 reps
Recomposition Phase (Fall):
- Squats — 275 lbs x 3 reps
- Bench Press — 225 lbs x 5 reps
- Pull-Ups — 12 reps
My lower body strength may have dipped slightly based on my reps at 275 pounds on squats. On the other hand, my upper body strength stayed about the same based on bench press and pull-ups.
Pictures of my workout logs highlighting weights and reps for heel-elevated (HE) squats. I also recorded my rest between sets (superscript next to exercise name) and total workout duration at the top. I apologize for the poor penmanship, as I just scribbled these numbers between sets. 😂
Overall, it looks like my strength level stayed about the same. This was a surprising result of the reduced protein intake, especially because I was in a calorie deficit for most of the year.
On the other hand, I wasn’t training for one rep maxes, so I can’t say if more protein would be better for maximizing strength gains.
Challenges & Unexpected Benefits
The first few weeks of the reduced protein experiment were, in a word, unsettling. I felt like I was “under-eating” protein, even though I was still consuming well above the recommended amount for average adults.
Some of the early challenges included:
- Mental Barriers: Years of ingrained belief that more protein equals better results made it hard to trust the process.
- Adjusting Portions: Meals felt smaller without the usual massive serving of chicken or a double scoop of whey.
However, within a few weeks, I noticed something surprising: relief. It actually felt liberating to be untethered from eating a giant protein portion every few hours.
Another unexpected benefit of reducing protein intake was a lower grocery bill. Protein-rich foods like meat are expensive compared to starches like rice and potatoes.
At my higher protein intake, I regularly ate about 16 ounces of meat daily. After reducing my protein intake, I only consumed about 4 ounces of meat a day.
- Estimated Cost Savings: Assuming meat costs about $4 per pound (averaging for poultry and red meat), the estimated savings by eating less protein is roughly $3 a day or $90 monthly.
Finally, I used to rely on 3 to 4 scoops of whey protein powder daily to hit my high target. With the reduced intake, I only used 1 or 2 scoops a day and got more of my nutrients from whole foods.
These screenshots show my post-workout meal protein powder usage in 2023 vs 2024. This year, I cut my protein powder consumption by over 50%.
Those are my results and experience with reducing protein intake. So, what did I learn from all this?
My Protein Intake Takeaways
This experiment taught me a lot about my body’s protein requirements. Here are the key takeaways:
- A protein intake of 0.8 g/lb was just as good for maintaining muscle as 1.4 g/lb in my case. This also jives with the meta-analysis showing a point of diminishing returns above 0.74 g/lb.
- A lower protein intake didn’t make me weaker. My performance in the gym remained fairly constant even while following a caloric deficit.
- Eating less protein gave me more meal-planning freedom. I wasn’t handcuffed to eating meat with every meal, and my grocery and supplement costs went down.
To be clear, my “lower” protein intake was still relatively high compared to the average person’s diet.
I also want to emphasize that protein is absolutely vital to building and maintaining muscle along with a resistance training plan. So, I’m not advocating anyone follow a low-protein diet.
But just how much protein you need depends on your unique body and fitness goals.
How Much Protein Do You Need?
In addition to my personal protein experiment, I’ve also worked with hundreds of clients as a fitness coach. In my experience, gram-per-pound benchmarks don’t work for everyone because body weight is not the only indicator of how much protein you need.
Your protein needs might differ from mine or others of the same body weight. There’s no single target or one-size-fits-all rule.
For example, I would be foolish to have a 300-pound obese client eat 300 grams of protein daily and use up 1,200 calories of their energy budget. It would be better to set their protein intake based on lean mass and necessary calorie deficit for weight loss.
On the other hand, I might have an underweight 160-pound client target more than 160 grams of protein with a calorie surplus to help them build muscle more effectively.
This graph illustrates why lean mass (not body weight) is the primary driver in how much protein you need.
These examples demonstrate how your protein intake should be based on your body composition, workout routine, and fitness goals. Not simply your weight.
Here’s how these factors can influence how much protein you need.
- Body Composition: Overweight or obese individuals probably don’t need as many grams of protein per pound of body weight since less of that weight is muscle mass. On the other hand, leaner individuals may require more grams per pound since more of their weight is muscle mass.
- Workout Intensity: You likely need less protein if you’re inactive or only work out at low to moderate intensity. While more active and intense lifters may be at the higher end of the protein intake spectrum to build or maintain muscle.
- Fitness Goals: Whether you’re trying to get stronger, build muscle, or lose weight may also impact your body’s protein requirements. Some people may require higher protein intake during aggressive calorie-restricted diets to prevent loss of lean mass. On the other hand, a recent study suggests that higher protein intake may have a smaller effect on strength and athletic performance. The lower impact on strength seems to correlate with my experience.
The gram-per-pound approach just can’t account for all these variables. That’s why I typically don’t use this strategy for figuring out protein targets for myself and my clients.
My New Method for Finding Protein Intake
One of the most significant realizations from my experience is that equating body weight to a protein target in grams doesn’t always work. So now I use a different method.
What I’ve found works better is calculating calories first, then setting protein intake as a percentage of calories.
I like this approach because it ensures I have the necessary energy balance for fat loss or muscle gain.
Here’s how it works:
- Calculate calorie needs using a formula that accounts for body weight, body fat percentage, activity level, and fitness goals. Let’s say your daily target is 2,400 calories.
- Then multiply your calorie intake by your desired protein percentage, like 25%. That’s 2,400 x 0.25 = 600 calories from protein.
- Now divide your protein calories by four since each gram of protein is four calories. That’s 600 / 4 = 150 grams of protein.
Finding your protein target as a percentage of calories takes a bit more math, but it’s also more personalized to your unique calorie and macronutrient requirements.
If you need more help finding your ideal calorie and protein targets, I also have a protein intake calculator that uses this formula.
