What Dr Michael Mosley thinks about weight loss medications 

The reason why I created The Fast 800 was because in 2012 I discovered that I had type 2 diabetes, and I wanted to get rid of it. During my research into how I could reverse my diabetes, I came across intermittent fasting, which I incorporated into my life. I lost 10 kilos and managed to get rid of the diabetes. It led me down a path of wanting to know more about how and why certain things like intermittent fasting, a Mediterranean-style diet and short bursts of exercise helped me to get rid of my metabolic disease, the type 2 diabetes. The Fast 800 was a result of wanting to share evidence-based information that pulled together everything I had learned.

Why I’m talking about GLP-1 agonists

The reason you’re hearing about GLP-1 agonists from me and The Fast 800 team is because they are obviously at the forefront of many people’s minds at the moment, and their use is very closely linked to weight loss and metabolic health. Indeed, we have a number of programme members asking The Fast 800 team about whether these drugs are okay to use alongside The Fast 800 Programme, and what they should be considering.

Now, originally these medications were developed to help type 2 diabetics, but have become used by people who simply want to lose weight. GLP-1 drugs are new in the sense that they are becoming widely available, although they have actually been around for some time now. I first came across GLP-1 medications nearly 15 years ago, when they were being tested by scientists at Imperial College in London. And at the time, they weren’t really that impressive, but since then, there have been a lot of refinements.

My initial thoughts on weight loss medications

Historically, I have been very sceptical about weight loss potions and pills because, frankly, they come with a long history of quackery and most of them have either been ineffective, or they have come with some really nasty side effects. What makes these drugs so different is they have been shown in randomised controlled trials to be both safe and effective. They are not without side effects. But having said that, compared to anything we’ve had before, they really are quite remarkable.

On the other side of it, of course, there has also been lots of evidence that when you stop taking the drug, hunger returns and the weight goes back on. Some people report feeling even hungrier, a sort of rebound reaction. So unless you have made lifestyle changes, then you will start to put on weight again, and quite a lot of that weight is going to be fat. One of the significant downsides of achieving significant, rapid weight loss with GLP-1 drugs is that you lose muscle when you lose weight, but when you regain the weight, a lot of it is fat. So, you may end up in a slightly worse position than you were when you started.

What you really want to do is lose fat without losing muscle, and unfortunately that doesn’t seem to be the case with these drugs. Particularly as you get older, it’s really important to preserve your muscle mass.

Recommendations for getting the most out of them

You might be thinking that GLP-1 drugs are an alternative to The Fast 800, but I would say they’re actually complementary. Using these drugs can be effective at helping you lose weight in the short term. But if you want to keep the weight off long term, then I would suggest that you’re going to need to incorporate a lot of the things we help you with on The Fast 800, which is learning how to eat more healthily, having a wide range of recipes you can call on, an exercise regime which will help you maintain your muscle mass, and also stress reduction techniques, which will help you when you are feeling under pressure. Because unless you have that backup system going, the danger is that in the long term, you will just put the weight back on again.

Like I’ve said, I think these drugs are remarkable, but I certainly wouldn’t describe them as miracles, because they do come with significant side effects and there are drawbacks. If they were miracle drugs, you would be preserving 100% of your muscle during weight loss, which is not the case with these drugs. I see that as one of their more significant drawbacks, plus the fact that if you stop taking them, the weight comes back on. A truly miracle drug would basically help you lose weight, then you’d stop taking the drug, and you’d just keep the weight off. That’s not what these drugs do.

A final word from me

So, I am essentially very, very pragmatic and, if it’s suitable for you, then combining one of these drugs with The Fast 800 Programme gives you the best of both worlds, in the sense that they will help suppress appetite, but you do really, really need some sort of programme, like The Fast 800 in order to change your habits, learn better ways of eating, have a wide range of recipes to call from in the future, do the exercise, get enough protein, all the things that we talk about on the programme, absolutely critical for long-term health. Simply losing weight is not in and of itself the end goal, but instead working towards a lifestyle that continues to support better health long-term.