The Biggest Lie About Weight Loss And Exercise

The internet is awash with people saying that exercise doesn't cause weight loss. This Vox video alone has over 13 million views. As a scientist myself, I find this statement incredibly misleading, a gross oversimplification, and potentially harmful. I'm going to explain why and give you some good information. Unlike many of the so-called experts on various podcasts such as the Diary of a Charlotte, CEO, I don't have a book, a supplement, or a health app I'm trying to sell you a subscription to. What I want is the same as you. I want to be able to manage my weight effectively and be able to lose weight if I need to. Let's take a look at what the science actually says. Before we delve into this, if you find these kinds of science videos useful and interesting, and I hope that you do, then please hit subscribe if you haven't already because it really does help support the channel and allow us to continue making videos. The first thing we need to address with this topic is that even if exercise doesn't help with weight loss, or more specifically, fat loss, then that's no reason to avoid it because there are a whole host of other benefits. Because I'm a cyclist, I'm going to focus on some of the benefits that are specific to cycling, which include, but are not limited to, the following. Improved cardiovascular health, which is the leading cause of death globally, according to the World Health Organization. You also get increased muscle mass, primarily in the legs if you're a cyclist, and improved metabolic health too, particularly with regards to blood sugar regulation and insulin sensitivity. There are also mental health benefits. Cycling can be therapeutic and a highly social activity that builds confidence. Even if exercise didn't cause weight loss, it doesn't matter. The benefits of it are so overwhelmingly positive, that's not a reason not to do it. However, by telling people that exercise doesn't help with weight loss, it misleads people into believing that they don't need to exercise in order to be healthy, and that health is just about weight. Experts often do throw in a slight disclaimer where they say that exercise is still beneficial, but this is done in a way that makes it often feel like it's small print. Who pays attention to small print? The internet is full of both charlatans and respected scientists making outrageous claims. For example, let's take Professor Tim Spector, a highly credible scientist, who when asked on the Diary of a CEO podcast, does exercise help with weight loss? He replied, all the long-term studies show it doesn't help with weight loss. That's an interesting statement because, well, here is a systematic review meta-analysis saying that it does, and here's another one, and another one. For those of you who don't speak nerd, a meta-analysis examines data from multiple independent studies to determine overall trends, and the independent studies that are placed within that are also ranked and weighted depending on their individual quality, and the first meta-analysis we showed you is actually from Nature, which is arguably the most respected scientific journal in all of science. What were the findings? Well, in the systematic review meta-analysis, where they compared non-exercise groups to exercise groups, they found there was greater weight loss in the exercise groups of 1.5 to 3.5 kilograms in weight. Crucially, we're talking fat loss there because in the better studies, they do body composition and dexascans. Now, that is a modest amount, but it still is weight loss. The majority of the scientific literature, when it looks into this, does suggest that exercise does help with weight loss. Why would someone like Professor Tim Spector say that it doesn't? If you were a cynic, you could say it's because of either cognitive dissonance, something which can affect even incredibly smart people, or perhaps it's an overemphasis in the importance of the microbiome and his own vested interest in a personalized nutrition company and app. However, there is another reason, and that's thanks to research carried out by a chap called Herman Ponser. Now, Ponser posed an interesting question. Who burns more energy in an average day? The average American sedentary office worker, think Kevin or Dwight Schrute, or a Tanzanian hunter-gatherer roaming the plains of Africa, hunting down antelopes while dodging lions. The answer is that they're the same. They have the same total energy expenditure per day, which is very surprising, and also helps explain why it's so difficult to lose weight through exercise. Ponser's energy conservation model suggests that when you increase physical activity, your body compensates by conserving energy elsewhere. Less fidgeting, more rest, and certain biological processes become down-regulated or up-regulated, and this is why overtrained athletes often experience decreased libido or their periods stop. His research found that hunter-gatherers had a lower body fat and were more active, yet their total energy expenditure was the same as sedentary Westerners. The key, though, was that some of the hunter-gatherers were fatter than other hunter-gatherers, and this was regardless of their level of physical activity. This suggests that the obesity differences stem primarily from the food intake, not the energy expenditure. The hunter-gatherers had, in general, a much better diet with little or no ultra-processed food. However, Ponser does acknowledge that there are outliers, such as ultra-endurance elite athletes. Take Tour de France cyclists or Michael Phelps and his alleged 10,000 calories a day as good examples. Now, the research hasn't looked at elite athletes yet, but it is consistent with how overtraining happens and also why Western recovery is so important. What isn't clear is whether or not you can train your body to take on higher training loads or higher levels of total daily energy expenditure. I suspect that you probably can, but that this is something that you'd have to build up over a long period of time and probably from quite a young age. If we take elite cyclists, a well-trained amateur can average 270 watts per hour. This burns 1,000 calories, which is loads. If we look at our very own Dan Lloyd, when he was a professional on the Cervelo test team, he could sustain 300 watts for four hours, which is 4,800 calories. Connor could do even more, 300 watts for six hours, which is 7,200 calories. By contrast, the average person might only be able to manage 300 or 400 calories per hour cycling, and they might even struggle to sustain it for an hour. Now, follow that up with a post-gym celebratory Mars bar, and it's very easy to undo all of your hard work gym gains. Hershey bar if you're in America. This is why taking into consideration the constrained energy model, I can agree with the statement that exercise doesn't help with weight loss at a population level. Most people won't lose weight through exercise because they don't do enough of it or they can't do enough of it. Meanwhile, a fit amateur cyclist can easily burn 2,500 to 3,500 calories on a long ride. Do that three, four times a week, and you're making weight loss through exercise much easier. Just make sure that you don't offset it with a massive piece of cake. This is consistent with what we see in the real world. I don't need a study because anecdotally, we all know people who are very lean and do a lot of exercise. Take, for example, the Tour de France peloton or your favorite fitness influencer. That's not to mention all the amazing messages, comments, and letters that we get from you guys, our viewers, sharing your own weight loss success stories, having taken up cycling and incorporated it into your lives. If you've lost some weight through cycling and taking up exercise, comment below on this video. The challenge with most studies though is that it's virtually impossible to get an overweight sedentary person and then get them to do 8 to 12 hours of exercise a week for a year. Most studies typically use exercise volumes much lower than that, less than 150 minutes a week. They typically last in the region of two weeks to a maximum of six months in the meta-analyses that we looked at. While it's true that losing weight through exercise is very difficult, I do firmly believe that it's possible with enough volume and consistency. What can we conclude from this? What are the key takeaways? Well, people want easy fixes. Being told that exercise doesn't help with weight loss is both convenient and very appealing. The Vox video even says, it's not impossible to lose weight through exercise, it's just harder. Yes, well, life is hard, but that's not a reason to discourage you from doing exercise. Personally, I cycle because I love it. It's a bit like that saying, do a job that you enjoy and you'll never work a day in your life. Find some exercise that you enjoy and combine it with a healthier lifestyle and a better diet and the results will come. The biggest takeaway from this is that diet is the biggest factor when it comes to weight management. You can't out-train a bad diet, but exercise also helps and it has a host of other benefits too. Your goal should be to improve your overall health and body composition. Eat less ultra-processed food, exercise regularly, probably incorporate some resistance training into that too, although that's a topic for a whole other video. Well, it's simple. Right, I'm going to go now. Love you. Bye.