How Bad Is McDonald's ACTUALLY? (30 Day Experiment)

Can you lose fat eating only McDonald's? Sounds ridiculous, but we decided to put it to the test. For the next 30 days, I've convinced Brendan, my videographer, to eat nothing but McDonald's to see if fat loss really is as simple as calories in, calories out, or if all that junk food has consequences on his body that I never could have expected. Day one, blood work. Day 30, blood work. Oh, man. This might not have been the best idea.

The last time I had a burger and fries, my body shut down.

So Brandon is someone who eats pretty clean every day, but over the last few months, he's hit a fat loss plateau. I've been trying to tell him the problem is less about what he eats and more about how many calories he's actually consuming. So when I told him he could technically lose fat eating only McDonald's, he was skeptical. All right, how about this? If this doesn't work, then I'm going to give you $1,000. Come on. Deal. Deal. Deal. Handshake. Deal. Let's go. So now that I've got my money and reputation on the line, it's time to create a McDonald's meal plan to get Brendan ripped. Okay, can I get two sausage egg McMuffin, one egg McMuffin, two pancakes, one apple pie, one peach pie, one egg BLT McMuffin, and. And then a large black coffee. All right, you excited? So, Jerry, there is no way I'm gonna lose weight eating this. Oh, dude, this isn't all for you. This is mine. Most of this is mine. I got you a black coffee. That one's yours. Great. Based on Brendan's current weight, to lose fat, he only achieved a daily target of 2,000 calories. But to avoid losing muscle and ending up weaker after the 30 days is up, you'll also need to hit a bare minimum of 120 grams of protein. There's your egg McMuffin. Today's breakfast is not a bad start. Coming in at what McDonald's claims is 290 calories and 16 grams of protein. But because these foods are so calorie dense, it's taken Brendan less than three minutes to finish eating. How you feeling after your big breakfast?

I should have worked for Jeff Nippard.

Now to see how all this highly processed food is affecting Brendan's body, he'll not only be doing a DEXA scan to measure his body fat and muscle mass, but we're also conducting pre and post blood tests. And we'll also be testing Brendan's strength before and after the Experiment to give us another way to assess if he's lost any of his hard earned muscle and strength. Good workout, dude.

Thank you.

Ready for lunch? What do we got? For lunch, I purchased Brendan a grilled chicken sandwich with just one tweet to lower the calories.

Is this no mail?

No mail. We had to make some sacrifices here and to give him a little bit of fiber and nutrition with his meal. Two bags of McDonald's apple slices. But even with what seems to be real chicken and apple slices to balance out his lunch, Brendan's already struggling.

It is 2:30 this afternoon and I already feel hungry.

But to help me truly understand what he's up against, I sat down with PhD researcher and published fitness author Dr. Lee Norton.

Even though this might sound like a fun diet to be on for some people, I think it's going to get pretty monotonous over time. If you don't have enough novelty, then you can get really bored of it and you don't have satisfaction from your diet and then your adherence can wane from that aspect as well.

Using Leon's advice, the meal plan I made for Brendan consists of three meals and two snacks per day. But rather than locking him into a strict meal plan, I gave him a few different options for each meal. He'll be logging everything into our new Built with Science plus app. So as long as he stays within his daily target of 2,000 calorie and at least 120 grams of protein, he's able to modify the meals however he likes. Lane, however, did raise some concerns.

I don't think I would recommend this diet. Right. This is kind of like, you know, probably about 15 years ago, a guy named Mark Haum, who is a professor at K State, did a what he originally called the convenience store diet or the 7:11 diet, but it got changed to the Twinkie diet. But he was eating 1800 calories a day from junk food. And he said, you know, I was pretty hungry for quite a bit. He said, you know, at first it was kind of cool to eat junk food, but after a while I just kind of wanted a really big salad.

So day one is in the books and I woke up today ravenously hungry. I was also up £1 on the scale. So I feel like I barely ate any food yesterday, but I am somehow hungrier and heavier than I finished yesterday. Come on, Jeremy. What are you doing to me? What are you doing to me?

But as it turns out, not every healthy meal option I selected was available in Canada.

Okay, I don't see any oatmeal on the menu at all. Can I get one of your grilled chicken salads, please? Do you guys have a grilled chicken salad? Grilled chicken salad, yeah. No. Okay, sorry. Could I get in that case?

And suddenly, the slate of meal options I originally planned out for Brendan was almost cut in half, so he had to start getting creative.

So I ordered their chicken wrap shredded, a little bit of the wrap, because that would blow my calorie target for the day. But I get to with this, have some tomato, cucumber, and then more grilled chicken. So doing a lower body day. And I know lower body sucks all the time. I can feel my heart just pounding out of my chest when I finish the set today. It is crazy hard. I don't know what it is, but it does not feel great.

Honestly, I don't think Brendan's racing heart has much to do with his new diet. He's not only been drinking extra coffee to help with his hunger, but. But he's also pretty nervous about what this diet might do to his health. And I don't blame him. Almost every item on the McDonald's menu is full of saturated fat, highly refined and stripped of pretty much everything that makes them good. It's also very limited. Apple slices are the only fruit Brendan will be able to eat over the next 30 days, and even their vegetables are questionable as a result. Aside from sodium, he's not even close to getting just 50% of most of his recommended daily nutrients, which honestly has even me concerned about what this is going to do to his blood work after 30 days.

All right, so we are into week two, and so far I am down exactly two pounds on the scale, which is pretty much exactly the rate of weight loss Jeremy was hoping for. So on that front, things are good. That said, there have still been some problems. For one, just because I am ordering low calorie, healthy meals doesn't mean McDonald's is always getting those orders correct. We have a fried chicken sandwich, and inevitably any mistake with an order winds up being a lot more calories, which makes it so much harder to still get my protein and stay under my calorie limit. Problem number two is that even when I get exactly what I order as I've ordered it, there is still such a low amount of fiber in this diet, and I don't even want to talk about why that is a problem.

Dietary fiber absolutely helps with stool elimination frequency and ease of elimination has been shown in numerous studies. So I think it'll still poop, but it might be Just a little bit less frequently and a little bit more difficult.

The recommended fiber intake for Brendan is about 35 grams a day on his McDonald's meal plan. However, he's getting less than a third of this, barely reaching 10 grams a day. And the blockage he's experiencing has definitely made accurately tracking his weight a lot more difficult than I anticipated.

So I am tracking my weight loss in Jeremy's app. And I think this is where you can really see the lack of fiber in the diet causing a problem. It just goes up, up, up for three days, then drops off weight immediately, starts climbing again, drops off. And this is solely tied to which days I am going to the bathroom, which makes it almost impossible to track because I am most days going up on the scale. And I can really only tell my progress based on those handful of low points. And it really feels like I am not seeing the progress I'm supposed to.

Let's see what damage we've done. And after two weeks on the plan, Brandon's total weight loss was only £1. Dang. I wasn't expecting that. But while Brandon was blaming his lack of progress on his low fiber intake, I was suspicious of a different culprit.

If he is in a calorie deficit, he will lose weight. If he doesn't lose weight, it will be because he was either sneaking food outside of it or because the calorie deficit amount was just a miscalculation based on the estimation.

So I did some deeper investigation into the claims McDonald's makes about its calories, and I found what might just be the true culprit. I think McDonald's is hiding, is hiding some stuff. I think they are heavily under reporting the calorie content of their meals.

I think that's 100% correct.

And like we saw it with the egg McMuffin, right? I mean, that was like what they listed it as 280 calories. So they're saying that egg plus an English muffin, bun plus ham plus cheese, American cheese plus what we didn't know was a spread butter on the bun. There's no way that's 280. That is at least, at least 400 plus. But there's another thing I completely overlooked that's making this calorie discrepancy even worse. So a 2023 study compared two groups of people eating the same number of calories, around 2100 per day. But one group ate highly processed foods with only 6 grams of fiber per day. The other group ate a less processed diet with 26 grams of fiber. And here's what they found. With the highly processed diet, about 95% of the calories were absorbed by the body. But with the less processed diet, only 89% of the calories were absorbed. The rest, they were excreted. So even though both groups ate the same number of calories on paper, the less processed diet led to an extra 116 calories lost in feces. Calories that never actually made it into the body. And here's the kicker. Nutrition labels don't account for this. So with Brendan's heavily processed diet, he may not be in the calorie deficit I initially thought he'd be, especially with all the hidden calories that McDonald's doesn't seem to take into account, which means no butter on his breakfast sandwiches and no sauces on his wraps and burgers.

All right. I feel like from an energy standpoint, I am doing better than I was expecting. It's not amazing, but I'm doing all right. What I never expected was to just be craving potatoes and spinach and bananas and just all the things I cannot get when I am at McDonald's.

As weird as it sounds, a cheat meal from Brandon at this point is whole foods. So let's get you a nice meal.

Oh, my gosh.

Beautiful stuff here. In the research world, cheat meals are referred to as planned hedonic deviation. And they've been shown to be an effective tool to help people stay on track with their diet. In Brandon's case, however, his cheat meal looks a little different. His body was craving nutrient fiber rich foods. How weird is it right now that this cheat meal is full of spinach? Look how he's so he is. And when he scanned his meal using our Built with Science plus app, he also realized he was getting way more food for a fraction of the calories.

So it is day 21 and I have just hit my lowest point on the scale yet. I am still seeing tons of fluctuation in my weight. But I have been consistently, week after week, hitting new low points, which seems like things are going in a good direction right now. I am just trying to push myself as hard as I can with every workout I do because I just feel like even though I'm losing weight, I am doing it on a McDonald's only diet. And that just feels like it's going to end up with me losing some muscle but really doing my best. And I do feel like I've gotten better at adding the most amount of protein for the lowest amount of calories. It's grilled chicken wrap, extra serving of chicken breast, extra cucumber, extra shredded lettuce, extra tomato.

This looks pretty good to me.

I be happy to swap.

We can swap meals. Right now.

I am on my way to get my final blood test and my DEXA scan. I feel like I have actually seen some relatively consistent progress on the scale.

These past two weeks, fueled by McDonald's. 30 days of McDonald's. Let's go. Up, up. Dude, that was nine, right? In fact, Brendan managed to gain two extra reps on both his bench press and pull ups. And he even matched his deadlift strength even though he forgot to wear his wrist straps. Limited his strength. Grip failed first. But the grip. Did you use straps last time?

Honestly, I can't remember.

But now it's time to see how his blood work has been affected. Oh, man. This might not have been the best idea. Why? Cause honestly, everything's fine, dude. All his blood work stayed pretty much the exact same, which is surprising. But remember how Lane mentioned Professor Mark Hobbies, who ate nothing but Twinkies and protein shakes for 12 weeks? He not only ended up losing 27 pounds, but all of his blood markers improved in the process. Turns out weight loss alone is a major health booster, and it can actually balance out the negative effects you'd expect from a nutrient deprived junk food diet. Which now begs the question, what actually happened to Brendan's weight?

Fat.

Fat and muscle mass. We go. I mean, you. You look lean, dude. Dang. I don't know if these are always here, but dang, dude, you look hella lean. Let's see. Let's see what the data says.

What?

That is the lowest for you. All right.

I knew I was down, but that.

After only eating McDonald's for 30 days straight, Brandon dropped five pounds on a scale, lost three centimeters off his waistline, and according to the results of his DEXA scan, your body fat dropped by almost 1%. Okay. And your muscle mass pretty much stayed the same. Let's go, man. McDonald's sponsored me. McDonald's, baby. This is the new Ronald McDonald. You looking at it now? While Brandon got some pretty impressive results, it was the most difficult five pounds to lose in his life. And if he ended up gaining weight on this diet, it's likely his blood work results would have painted a much different story. But this experiment does show you how fat loss really is. A numbers game. So if having your favorite burger or ice cream every now and then keeps you on track, go for it. As long as you're aware of how quickly those calories can add up. But you if if you're someone who has tried counting calories in the past and found it too tedious or it just didn't work, then I've got some good news for you. With my brand new Built with Science plus app. You can just snap a picture of your meal and it'll instantly estimate the calories and portions for you and log it directly into the app. Plus you'll be able to track your workouts, body weight and progress all in one place. I guarantee it is the only fitness app you need and as if I was personally coaching you every single week. And you can try it for two weeks free and see the difference for yourself over at built with science.com and then you can also watch this video here for a tasty high protein fat loss meal plan to get started with right away. Thank you so much for watching. Hope you enjoyed this one. I'll see you next time.