Tiêu đề Refeeds versus Diet Breaks.pdf ✅

Refeeds versus Diet Breaks Refeeds and Diet Breaks So, as a physiological silver bullet, refeeds didn't pass scientific muster. Single-day high-carb refeed days, while able to produce significant spikes in leptin, weren't able to produce fat loss outcomes any better than regular calorie restriction. But the researchers didn't just give up on the idea. Instead, they explored what happened when a refeed was extended over a longer period of time. This is where we get diet breaks. Diet breaks her typically 3 to 14 days of consecutive eating at maintenance or more. Most people refer to diet breaks as a week or two. A few days typically isn't considered a diet break. Interestingly, research by Bill Campbell's lab at the University of South Florida, examined doing back to back refeed days at maintenance and they found that lean body mass preservation was better, slightly better fat loss, and slightly better preservation of metabolic rate versus continuous dieting even when they equated weekly calories (Campbell et al., 2020). That may seem really great, but it's worth noting that the difference in BMR preservation was only 70 calories per day between the different groups. Now that is still a significant difference, but it's almost at the limits of detection for the apparatus being used. So I want to see more research before I make really strong recommendations regarding consecutive day refeeds, but at least it seems encouraging. Now, there've been a number of research groups who have looked at extended diet breaks. Perhaps the most popular and convincing of these studies was the MATADOR study. The study was specifically constructed to test not only the impact of intermittent energy restriction versus continuous energy restriction on fat loss, but also to study what happens after the diet. Rebound weight gain can be a real problem for those who diet hard to get very lean but don't have a good exit strategy to recover their metabolism. We'll get into the specific finding on both those questions in a little while, but first a quick note on terminology. There are a lot of wannabe scientists in the fitness industry, and you can spot them a mile away. They're the ones who copy and paste from the abstracts of scientific studies as if they found the truth. Worse, some will just copy and paste the headline written about the abstract. In either case they're not looking at the actual evidence. I've seen it happen, especially with the MATADOR study and other studies like it.
You see, when academics write about their research, they use terms that have specific meaning to their field of study. They don't really care that some shitty Insta- coach uses the same or similar words to mean something else. I mentioned before that the MATADOR study compared intermittent energy restriction versus continuous energy restriction. You might look at the term intermittent energy restriction and assume we're talking about something other than what was studied. For example, it may remind you of intermittent fasting, but be careful about conflating these things. They are not the same. Intermittent energy restriction or IER, refers to the alternating periods between calorie restriction, ie. being in a negative energy balance and maintenance. Intermittent fasting, on the other hand, is constraining consumption of calories to a relatively narrow feeding window over the course of a day. Just because they both use the word intermittent doesn't mean that the same or even related to each other. Okay now back to our regularly scheduled program. The MATADOR study looked at two populations of people. Both were calorie intake controlled and monitored for a 4 week baseline period, then incurred a 16 week period of energy restriction of 33% below their TDEE and then did a post diet maintenance phase of 8 weeks. The difference between the two study groups was one stayed in a caloric deficit for a continuous 16 week period, while the other group alternated between 2 weeks of caloric deficit and 2 weeks at maintenance calories. This was the diet breaks group. The diet breaks group still had the same 16 weeks of calorie restriction, but the overall diet period extended them from 16 weeks to 30 weeks to accommodate the 7 additional 2 week periods that they were at maintenance calories. Both groups being calorie controlled, were delivered all of the food to their homes and they both were measured at the same equivalent intervals throughout the study period. The results were pretty cool. The group on the continuous calorie restriction diet predictably lost weight. They lost quite a bit of weight. After 16 weeks of eating at a 33% deficit they lost 8kg. From week 17 to 24 they were fed a calorie controlled diet at maintenance and you can see that the weight started to come back a little bit. As a group they gained back 1kg on average during this period. They were measured one more time 24 weeks later, so 48 weeks from the start of their calorie restriction, and they manage to get back to roughly close to where they started. This looks like you're a typical
gen pop yo-yo diet, right? Big dip during the deficit, slowly but surely the pounds come back on. So what happened with the diet break group? Well, they lost significantly more weight than the continuous restriction group. They lost almost 5kg more on average, and after 8 weeks of maintenance their weight didn't really change that much. They managed to keep most of the lost weight off even after having dramatically higher calories. But what about the follow-up period? Surely they must have gained it all back? Well they gain some of it back but they managed to keep the majority of the lost weight off. As it turns out, at the end of the 48 weeks, the diet break group managed to still be 1kg lighter than the continuous food restriction group at their point of highest weight loss. That's right. The group with diet breaks were better at their worst than the continuous dieting group at their best. The MATADOR study gives us pretty compelling evidence to base our use of diet breaks, but it's important to remember that like anything having to do with metabolism, there is no free ride. First, although the weight loss results with diet breaks were indeed better and the retention of that weight loss was better, it also took 14 weeks longer to produce these results than with continuous dieting. In a world where so many competitors expect to win a show on a 12 week prep, how practical is it going to be to push 30- week long contest preps just so you can implement the methods in the MATADOR study? Second, not everyone's going to want to use diet breaks. There are a lot of people who need to get into a diet rhythm and stay there. Breaking up that diet rhythm tends to make them more stressed and be less adherent. There's no point trying to force someone like this to change their macros every 2 weeks just because the MATADOR study says they'll lose more weight. If getting out of the groove is going to put adherence at risk, then you're better off sticking to continuous restriction. Without adherence it doesn't matter if you use refeeds or diet breaks, you're not going to get results. Third, even if you're comfortable with switching up your macros every 2 weeks and you have the time, you may find it difficult to execute the switch. The MATADOR study used a 33% deficit. That's a really big deficit. Having to switch from TDEE to 67% of your TDEE every few weeks means having to constantly readjust to dramatic
reduction in calories. This can introduce its own source of psychological stress that may not end up being worth it in the end, especially if it impacts adherence. Now I think the MATADOR study is great. As a PhD researcher myself, I have a lot of respect and appreciation for the work contributed to science this team delivered. That said, it doesn't mean you have to implement the protocols of the MATADOR study precisely in order to make a science-based intervention on yourself for a client. In fact, I really couldn't argue with you for using different protocols from the MATADOR study because I myself use varying protocols depending on the situation. You see, the thing about studies like the MATADOR study is they can tell you whether something is likely to produce a result or not, but they can't tell you everything that would produce a result, and they certainly can't study just one approach and conclude it's the best of all possible approaches. Science doesn't work that way. In fact, they might've just found the second worst way to diet. We just know it's better than continuous. For example, the MATADOR studies specifically looked at 2 weeks of calorie restriction, followed by 2 weeks at maintenance. Is a 2:2 diet break schedule better than a 2:1? Better than a 3:2? What about a 3:1? Or 4:1? I don't know, and neither do the researchers behind this study. They didn't ask that question as part of their study design so naturally the study doesn't get to answer that question. So what am I getting at here? My point is just because the MATADOR study used a 2:2 schedule doesn't mean that other schedules aren't as effective or possibly even better. It just means that because this research team looked at 33% caloric restriction doesn't mean that a 20% or 15% reduction wouldn't also produce results. It means that just because the MATADOR study use 16 weeks of total calorie restriction doesn't mean that 12 weeks couldn't be used or that 24 weeks couldn't be used. My point is that how we apply the findings of the MATADOR study in our practice is our choice. We're not completely bound by the design of the study. In my practice, I tend to use a 2:1, 3:2, 3:1 or even 4:1 ratio. This gives me a good balance between controlling metabolic adaptation and not overly prolonging the prep. I also don't see a reason why you couldn't mix and match durations to suit your needs. If you think about it, it makes sense that you would. The whole point of diet breaks is to minimize metabolic adaptations to negative energy balance. We know that these adaptations accelerate the leaner you get. That's why someone who's obese and goes on a diet will lose nearly all their weight from adipose and not lean tissue. In the presence of so much excess body fat, there's really no reason for the