Most replayed moment: The surprising science of weight loss | Alan Aragon & Professor Sarah Berry

**SPEAKER_1** (0:01)
Hello, and welcome to ZOE Recap, where each week, we find the best bits from one of our podcast episodes to help you improve your health. Today, we're talking about fat loss. For decades, we've been chasing the perfect weight loss diet. From Atkins to carnivore, countless trends have promised remarkable results, yet failed the test of time. So how do we cut through the noise and find a formula that actually works? In this episode, I'm joined by nutrition researcher, Alan Aragon and Professor Sarah Berry, to unpack the science behind sustainable fat loss, and explain why in some cases, the first step towards losing weight might actually involve gaining a little first.
Alan, why are we becoming more overweight?

**Alan Aragon** (0:49)
It's a combination of several things. So the way that I see it, it is a gradual shift towards sedentary living, and this has been facilitated by labor-saving devices, and even electronic and digital means to not even have to get up off the couch to prepare food. You just make a call and then wait for it to show up at the door and that's it.
In addition to that, there's a fundamental misunderstanding of how to maintain healthy body weight, and people simply don't know or are unaware that fundamentally, in order to lose weight, you have to impose a net caloric deficit over a period of time. And so when people are not aware of that, then they easily believe that there are magic foods that, for example, burn belly fat, or magic foods that burn fat, and then other foods that you should completely vilify or avoid. And that's where a lot of the confusion comes in. And in addition to that, I would say that, in the present time, people have a greater tendency to use food to, I guess, medicate or entertain themselves, just from general work, stress, interpersonal stress, anxiety.
And so food ends up being kind of used as that sort of tool. I think that the combination of those things is at least some of the factors underlying the obesity phenomenon that has basically started in the early-ish 80s and continued on to today.

**Sarah Berry** (2:28)
To add to what Alan said, I do think, as well as the fact that we're more sedentary, as well as we're all living such different lives and we have all of this food noise, our food landscape and the food choices that most people are making now are so, so different, 20, 30, 40, 50 years ago.
And they're almost hijacking our system. You know, we have evolved to be able to handle excursions in blood sugar, to handle fat, to handle all sorts of things that are thrown against us. But we haven't evolved to handle the food landscape that's out there, that's evolving even more quickly than science can evolve.

**SPEAKER_1** (3:04)
Maybe we can imagine a new client, Alan. So let's say they're in mid-life, they want to lose, say, 10 pounds. Where do you start and could you take us through the journey with them sort of step-by-step?

**Alan Aragon** (3:19)
Okay. So not everybody is ready to go on a program where they transform their body. Okay. Let's say somebody thinks they're ready. I would start with, let's see your sleeping cycle. How much sleep are you getting? Do you feel it's enough? And what is your history with regard to that? Because sleep is the X factor for a lot of the success or failure in programs. Because when you don't get enough sleep, not only does it kind of affect the obvious stuff, meaning your energy to be physically active and certainly your energy to engage in any kind of progressive training program, but it also increases your appetite and your cravings, your hunger levels, and increases your cravings for calorie-dense, hyperpalatable foods. That's what sleep-deprived people mostly reach for almost instinctively.
There's some very interesting research showing that subjects who are sleep-deprived consume, across studies, on average, about 200 to 300 calories more per day while they're sleep-deprived.

**Sarah Berry** (4:26)
There are studies where they actually take people into these kind of chambers, and they monitor them for weeks, and they actually sleep-deprived them. They say, right, you're going to become a short sleeper, so less than six hours. And they see, anywhere between 150, 300 calories per day increase, in how many calories they're having, just from depriving. I mean, it's a pretty cool study that these guys do.

**Alan Aragon** (4:49)
Yeah, and the interesting thing is, it went the other way, too. They took a group of habitual, less than six and a half hour sleepers, and they put them through a coaching and training, sort of this education program on how to improve their sleep hygiene, and the goal was to add two hours of sleep a night. So, they wanted to bring them up to, I believe, eight and a half hours or so. Seven hours of sleep appears to be this sort of threshold, where below that, the outcomes are somewhat adverse.