# I Tested 3 Muscle Building Diets, Only 1 Was Worth It ## Метаданные - **Канал:** Jeremy Ethier - **YouTube:** https://www.youtube.com/watch?v=D6Qw2dfrFRg - **Дата:** 22.02.2026 - **Длительность:** 17:50 - **Просмотры:** 406,604 ## Описание Start a free two-week trial of BWS+ here: https://bws.plus/13a How much muscle can you really build in just 90 days of bulking? And more importantly — how can you do bulk without gaining fat? To find out, I tested the three most popular muscle-building diets (including a lean bulk) on my brother-in-law Dayton. By the end, you’ll see how much muscle he gains, which one builds muscle fastest, which one burns fat while building muscle, and which diet completely backfires so you know how to bulk up without getting fat. Last year, Dayton dropped from about 33% body fat down to about 17%. After that cut, he wanted to bulk up for a bigger physique — permanently — and not gain fat again. So we ran a 90-day experiment that tested what actually happens when real life hits. To measure the changes, Dayton got DXA scans before and after each 30-day bulking diet. And because short term DXA’s can be less reliable, we also used ultrasound/skinfold/circumference measurements. He tracked every workout in the Built With Science+ app so we could compare strength gains in the gym to new muscle growth. Days 1–30: Accidental lean bulk We started with maingaining: train hard while eating just enough to maintain your weight. Dayton’s maintenance was right around 2300 calories, with at least 100g of protein per day to leave room for carbs to fuel workouts. Training was 5 days a week using dumbbells, a bench, and a pull-up bar, with extra focus on the back and the lats he was convinced would not grow. But ten days in, stress piled up. At our family’s Filipino Thanksgiving, he ate until he was sick. And he was dealing with losing his grandpa to cancer — his father figure after his dad passed away when he was seven, also from cancer. Even with all that, he did not miss a single workout. At the day 30 check-in, he was up about 1.8 pounds, so we swapped the order and treated this block like a lean bulk. Result: an estimated 1.35 pounds of muscle gained, with some fat gain but not excessive. Days 31–60: Fast bulk Next we cranked calories up to about 2800 per day, roughly 500 above what he burns. We mainly added carbs for glycogen and energy so his workouts could really get taken to the next level. Dayton felt so good he started adding sets, and the extra momentum even benefited his business once he started posting more transformation content. But he also started noticing more belly fat. At the day 60 check-in of our “how to bulk up without getting fat” experiment, he gained about 4 pounds in 30 days, felt bigger and fuller, and his pull-up strength since day 1 had doubled. He gained an estimated 1.8 pounds of muscle — about 30% more than the lean bulk — but he also gained about 3x more fat than during the lean bulk phase. Days 61–90: Maingaining For the final 30 days, we brought calories back down to maintenance. Muscle growth needs energy, but that energy does not have to come directly from extra food when you have stored body fat. Dayton got creative with lower calorie treats like a chocolate peanut butter frozen yogurt that tasted like a peanut butter cup with some banana, kept training hard, and finally had a workout buddy after convincing his brother to move in. Training became more than just building muscle — it helped keep him sober. Routine kept him grounded. At the day 90 check-in of his bulking journey, his bodyweight was essentially unchanged from 30 days earlier. He gained an estimated 1.1 pounds of muscle, and for the first time in the experiment he actually lost a bit of fat as his waist tightened up. Final results Over 90 days, Dayton gained roughly 4.4 pounds of muscle — with only dumbbells, a bench, and a pull-up bar. Fast bulking delivered the most gains but came with disproportionate fat gain. Maingaining was surprisingly effective and helped him lean out. But for Dayton’s goal of building muscle before attempting to cut to 12% body fat for summer, the lean bulk made the most sense. And at the end, I surprise Dayton and his brother with a new gym setup so they can keep building. This is how to bulk according to your body and goals. Maingain Who • Higher body fat lifters (≈20%+) • Returning to the gym after time off • Want muscle without bulking How • Eat at maintenance calories • Keep bodyweight the same Lean bulk Who • Novice/intermediate/advanced lifters • Muscle gains have slowed down • Want to stay lean while gaining How • About 250 calorie surplus • Gain about 1% bodyweight/month (about 1–2 lb/month) Fast bulk Who • Naturally skinny lifters • Brand new lifters (newbie gains) • Struggle to gain weight How • About 500 calorie surplus • Gain 2–3% bodyweight/month (about 3–5 lb/month) Timestamps: 0:00 - The 90 Day Experiment 0:40 - Diet #1 5:26 - Diet #2 10:00 - Diet #3 15:44 - Which Diet Is Best? Click below to subscribe for more videos: https://www.youtube.com/jeremyethier/?sub_confirmation=1 ## Содержание ### [0:00](https://www.youtube.com/watch?v=D6Qw2dfrFRg) The 90 Day Experiment How much muscle can you really build in just 90 days? And more importantly, how can you do it without gaining fat? To find out, I'm testing the three most popular muscle building diets on my brother-in-law. So, by the end of this video, you won't just find out how much muscle he gains, but which one builds muscle fastest, which one burns fat while building muscle, and which diet completely backfires. — This is a bit of a disaster. So, last year I helped my brother-in-law Dayton drop from 33% body fat down to his current body fat of 17%. And now he's hungry for more. — Now that I've cut, I really want to bulk up, get bigger at all. I'm not getting fat again. Like, I refuse to get fat ### [0:40](https://www.youtube.com/watch?v=D6Qw2dfrFRg&t=40s) Diet #1 again. — So, to help Damon with his goal, I'm starting him off with our first diet, maintaining. The theory here is that by training hard while eating just enough to maintain your weight, your body is forced to burn off your body fat to fuel muscle growth. And to measure if that actually happens, Dayton's getting DEXA scans before and after each diet to see how much his muscle and fat changes. But because short-term DEXA can be less reliable, we also took ultrasounds, skinfold, and circumference measurements to get a more complete picture of which diet actually works best. Now, to set up his main gaining diet, if you take your body weight in pounds and multiply it by 13 to 16, depending on your activity level, that's roughly what your body needs to maintain. But I know from personally working with Dane for so long, that his current maintenance is right at 2300 calories. And this is a sample day of eating I've created for him to hit that target. As for protein, Dne's targeting at least 100 g of protein per day. Now, while that might sound low, some new research suggests that if you're eating enough calories and you're not bodybuilder level shredded, then your protein needs aren't nearly as high as most people think. In fact, if you take your body weight in pounds and you multiply it by 0. 7, that's already enough to maximize your gains, which gives Dayton more room for carbs to fuel his workouts. — I got my veggies, lean protein, and my carbs. We're 7 days in. My weight hasn't moved. We're doing good. But what's going to have no doubt the biggest impact on his gains is his training. So I'm having Dayton train 5 days a week using my personal favorite workout split. And the plan seems to be working. He's sending me PRs every workout. And with his app, we'll be able to see how much his strength gains from each diet match up to actual muscle growth. But just as the going was getting good. — All right, guys. Quick update. So, I just realized that both of my roommates are moving out, and that leaves me with only two months to find replacements. If I don't find someone, that's going to leave me with a lot of money to pay all on my own. And on top of that, my business is hit a dry spell. It's the slowest it's been for a long time. So, that's a lot of stress right now and it's making it a little hard to stay on track with the workouts and the diets. — With all the added stress, he began snacking a lot more than usual. And it also didn't help that this was filmed during the holidays where he couldn't resist my mom's Filipino desserts. — I got my third plate of the night, a dessert. It's called ube and then some sort of rice pudding. — But then something happened that might just end this experiment altogether. Um my grandpa, he passed away a few weeks ago uh from cancer and he was a big male role model for me as uh my dad passed away when I was seven also from cancer. So he was my father figure. So yeah, it was honestly a tough time for our whole family, but especially for Dayton. And even though he could have easily quit the experiment, he stuck it through, not missing a single workout. And even though he tried his best to stay on track with his nutrition, when he returned for his second check-in on day 30, the results weren't quite what we had planned. You actually gained 2 lb of body weight. Now, the goal was to maintain your weight as best as possible, and the next phase, the goal was actually to gain 2 lb — in a month. Oops. Luckily, his overeating actually lines up perfectly with the next diet that we had planned, a lean bulk. That's where you take your maintenance calories and you bump them up by about 250, which typically results in around 2 lb of weight gain per month. So, we decided to swap the order of his diets and save the main gain diet for the very end of our experiment. The good news is that it seems like those extra 2 lbs went to the right places. Okay. — Based on Dayton's results, combined with the data from our additional measurements and scans, after 30 days of lean bulking, he's gained an estimated 1. 35 lb of actual muscle. As for whether that's good or not, in a 2020minut analysis from a huge number of short-term training studies, participants gained roughly 2. 4 lb of actual muscle, but it took them 10 weeks to do. So, Dayton's definitely above average. Plus, the last time I seriously assessed my own rate of muscle gain, it took me 60 days to put on just half a pound of muscle. So, Dayton clearly still has the ability to build muscle quickly. As for fat gain, based on the data from his belly skin folds, ultrasound, and waist measurements, he did gain some fat, but it wasn't excessive. So, overall, DNE's lean bulk was quite the success. But, it does beg ### [5:26](https://www.youtube.com/watch?v=D6Qw2dfrFRg&t=326s) Diet #2 the question, can we speed up his gains further if we feed him even more? So, for the next 30 days, we're running a fast bulk, cranking his daily calories up to 2800. That's 500 calories more than his body burns every day. — You're probably wondering like where what types of calories should I be eating? — Yeah, right. — You're getting enough protein. So, my personal recommendation is if you're going to add calories, let's do it from just pure carbs. — Okay. — Cuz that's what's going to give you the glycogen and the energy that you need in your workouts. that we can see your workout performance just like really be taken to the next level. So, it's not like we're taking his diet from this to this. We're just making small daily changes so that he gains roughly 4 lb by the end of the next 30 days. I can have a little bit more rice, a bit more carbs, some more sauce, but I have to stay on track. I have to weigh everything. I can't make the same mistake I made last time. — I'm just hoping he doesn't overdo it. Yeah, my roommate came back from Mexico and he came back with a giant bag of candycoated sugared peanuts. And I love candy covered peanuts. So, I did crush a lot of these. But at least Dayton was putting these extra calories to good use. — So, I think Jeremy's right about upping the carbs. I've been hitting PR after PR. I have a lot more energy and I'm just feeling way stronger. Ding felt so good that he actually started adding more sets to his workouts. And normally studies would never allow for this. Workouts are kept identical. So the diet is the only variable, but I honestly think that misses a huge indirect benefit of eating more calories, the extra energy to train harder and longer. So instead of holding him back, we let him loose. Whether it leads to more muscle growth, we'll find out soon. In the meantime, as his body transformed, so did his business. His Tik Tok fitness videos drove traffic to his business content, and that attention turned into orders. So, I got some exciting news. My brother is currently looking for a place to live and I so happen to be looking for a roommate. He's really into working out and we have tons of things in common and we uh get along really well. So, I really hope it works out because I need a roommate. — And while Dean's work and roommate search were improving, he was now dealing with one major downside of his fast bulk. I've definitely been noticing a bit of extra belly fat. Uh I've gained a little bit of weight as well in my face. I can see I've gained just a little bit of weight. Those are the two spots I always notice that my face gets a little chubbier in my belly. We'll find out soon whether that's just in his head or not. But there are a couple factors that should be working in Dayton's favor. For starters, a study on untrained lifters found that a fast bulk led to huge muscle gains over the course of 8 weeks with minimal fat gain. But when that same fast bulk was tested on more experienced lifters, most of the extra weight gain now came from fat rather than muscle. In other words, fast bulking seems to work best when your body can actually use those extra calories to build muscle. And I learned this the hard way. When I first started lifting, I did a dirty bulk. sometimes even drinking a gallon of milk a day and it worked. I put on a lot of size without much fat. But when I tried that same approach a few years later, it just made me fluffy and I had to spend months dieting the fat that I gained with very little extra muscle to actually show for it. And while Dayton isn't a total beginner, as he's still in his first year of proper training, there's a possibility that the fast bulk actually works out the best for him. The last 30 days, you've gained 4 lbs. Okay. What have you noticed? strength, overall size. I just feel bigger. — I have more energy. I feel strong. Definitely did. Yeah, I've noticed a little bit of fat gain, but that was to be expected. — Well, you look fuller, dude. Even just in this shirt, like your arms, — your chest, — I feel a lot bigger. — And his pull-up strength since day one has actually doubled. Let's go. One more up. Look at this new Zach. You can see it through the shirt. V taper. You look like a ninja turtle. As for his muscle and fat results, Dean gained an estimated 1. 8 lbs of muscle, 30% more than what he gained during his lean bulk. But it did come with a trade-off. This time, he gained three times more fat than during lean bulk. And I've seen this quite a bit. People fast ball, they put on size and fat, and then they hit a point where the fat gain is so overwhelming, they never actually cut to get rid of it. Luckily, Dane was still ### [10:00](https://www.youtube.com/watch?v=D6Qw2dfrFRg&t=600s) Diet #3 looking relatively lean. And with the extra fat that he gained, it actually put him in the perfect position to take another shot at our last diet. Meaning gaining, which means that you have to maintain your weight. No more tons of ground beef. I have to go back to chicken and jerky. Okay, I know what's coming. — And while Dayton may not be thrilled about scaling his calories back, if he sticks to the plan, he should still be able to build muscle and instead of gaining fat, actually lose some. That's because while muscle growth does require energy, that energy doesn't have to come directly from the food you eat, most people carry well over 100,000 calories stored as body fat. And your body can tap into that energy to fuel muscle growth. In fact, when Dayton first started working with me on a fat loss diet, he was still able to build muscle, not as fast as during his bulk, but at a pretty solid rate of about 0. 7 lbs of muscle per month. and instead of gaining fat, he was losing about 5 lbs of pure fat each month. And he's not some rare exception. We see it all the time in studies, and I've seen it countless times with our app members, even people who have trained for years. They start dropping fat while building new muscle because for the first time in their lives, they're actually following a proper plan. And that is exactly what our app does for you. You enter your info, it gives you a personalized diet and training plan so you quickly see results and then it adjusts your plan over time based on how your body responds. And you can try it completely free for 2 weeks over at buildwithcience. com or by scanning this QR code right here. All right, guys. In order to keep the ground beef in the diet, I've been mixing extra lean ground beef with lean ground turkey. That way I can keep the fat down and the flavor up. And if you put enough seasoning in, you really can't tell the difference. Now, while his fast bulk had more room for sweet treats, this time Dean had to get creative. — So, I came up with a snack that's kind of like a chocolate peanut butter frozen yogurt snack. And here it is. M. Really good. Kind of tastes like a Reese's peanut butter cup but with some banana. And while I was worried Dean's energy might take a hit, he seems to be training just as hard with his new workout buddy. — So, I got my new roommate and it's actually my brother and it's been really nice having him around. We've been working out together, hitting PRs together, pushing each other in the gym. Today, we're doing dips. I'm going to try and beat my PR. One, two, 24. Get 25 24. — Not only that, but they started prepping meals together and keeping each other accountable. But to Dton and Cole, sticking to their training is more than just for building muscle. — I've been working out the last year and a half. Before that, I was an addict for 10 years, living on the streets, getting in trouble. Uh, pretty much weighed nothing. Now look at me. after dealing with the loss of my grandfather. It's really got me thinking about family, how uh me and my brother lost my parents at a young age. I really haven't had my brother in my life for about 10 years due to his own struggles. So, I'm just really happy that he's uh doing better and he's going to be living here. — And while Dane was enjoying his time training with Cole, his progress on the scale was completely stable, which is exactly what we want. But it was now hard for him to tell if he was making any actual progress. But research shows that if you keep your exercises the same week after week and your strength is going up, especially in the 6 to 12 rep range, that is a very strong sign that you are building muscle regardless of what the scale says. Now, we'll see if that's actually true for Dayton. But I'll be honest, main gaining is just not for everyone. If you're already pretty lean, say under 15% body fat for men or 25% for women, your body may not have enough stored energy to reliably fuel muscle growth, which can leave you spinning your wheels. And if you're underweight, like I was growing up, you're not going to gain 20 lbs by main gaining. But if you have enough body fat, you're newer to training, or you've just never trained or dieted properly, main gaining can be a great alternative to constantly cycling between bulking and cutting. Which is why at the end of the video, I'm going to showcase the results from all three diets and explain which one will work best for you based on your body. And bro, you are a master of maintaining your weight because your weight is the exact same as it was 30 days ago. Before I show you the Dex results, let's pop open the hood. Now, keep in mind that Dane did all of this with only dumbbells, a bench, and a pull-up bar. And what he doesn't know is I'm going to be surprising him with a brand new gym setup to help him and his brother continue the journey. But before I surprise him, let's review the results of his final diet. Starting with muscle gains. Dude, look at this chest, man. Every time I see it, it's just like ballooning up. Holy. So, after 30 days of his maintained diet, Dayton gained an impressive 1. 1 lbs of muscle. That's only 15% less than his lean bulk and 37% less than his fast bulk, leading to a total of roughly 4. 4 lb of muscle over the whole 90 days. But what's interesting is his strength gains during each diet actually match quite well with how much muscle he ended up building. So, if you don't have access to fancy scans, tracking your lifts is an easy and pretty reliable way to assess your gains. Now, as for fat gain, for the first time in our experiment, rather than gaining, he actually lost a bit of fat. His waist tightened up and some of his belly fat actually came off. Which ### [15:44](https://www.youtube.com/watch?v=D6Qw2dfrFRg&t=944s) Which Diet Is Best? brings me to our final question. Based on the results of all three diets, which one worked best and is the approach I'm going to actually recommend for Damon? Well, while the fast bulk delivered the most gains and he did enjoy the extra food, it came with a disproportionate amount of fat gain, which I know Dayton would end up regretting. As for main gaining, I was honestly surprised with how much muscle he still built. But since I know he felt the best with more calories, and he does want to prioritize building muscle before attempting to cut to 12% body fat for the summer, the lean bulk, it just makes the most sense for now. But that's just my take for Dayton, and it might very well be different for you. So, I wanted to make this chart right here to help guide your decision. But just keep in mind that in all three diets, Dayton still made tremendous progress. So, I don't want you to overthink it. Eating well and training hard is what's going to drive most of your gains. And as for which diet, Dayton's decided to stick with a leaner bulk. I think if we stick to that, I don't get too much belly fat over the next few months, then I can hit that 12% easier. Won't feel like I'm giving up. so much. — True. And to help Dane get there, it's time to reveal the surprise that I prepared for him and Cole. — Yo, you went overboard, dude. — I don't think you know what this thing can do. — I don't. That's what I mean, dude. I have no idea. I got you a barbell. I got you weight blades. I have more weight plates coming. — Crazy, bro. — How's your whole experience been? — Amazing. I mean, my whole life changed for so many positive ways. just diet, my energy, everything's just been overall better. And it's thanks to you and your app. It's just so nice to not have to overthink. It's just it does all the little things, the monotonous stuff that no one wants to do. It just takes care of all of that. — If you guys want to give the app a shot, you can get two weeks free at billscience. com or scan this QR code right here. And if you guys want to try out a full body workout plan that's all done for you, then give this video a watch --- *Источник: https://ekstraktznaniy.ru/video/18450*