Posted June 08, 2017 12:14:06

The diet book industry is a global behemoth that has spawned hundreds of titles over the years.

From the Atkins diet to the paleo diet and lemon detox diet, there is no shortage of suggestions for how to lose that unwanted weight.

Dr Michael Mosley has built a career out of presenting TV shows on medicine and biology and in the last few years has turned his attention to diet books.

He popularised the 5:2 diet — which calls for minimal calorie intake for two days a week and having unrestricted eating for the other five — and more recently he has released books titled The Fast Diet, The 8-week Blood Sugar Diet and the Clever Guts Diet.

Photo: Dr Michael Mosley is a familiar name in the diet world. (Supplied: Dr Michael Mosley)

Read an edited Q&A about his growing body of work.

Aren't these all just fad diets?

Absolutely not. They're all based on the latest science.

So the 5:2 diet is based on more than 40 years of research and the guy who inspired me most was Professor Mark Mattson, who is probably the world's most famous neuroscientist.

The blood sugar diet was different, it was an extension. That is based on the work of Professor Roy Taylor, who is one of the world's foremost diabetes specialists.

And this new thing, the Clever Guts Diet, is not really a calorie restriction diet, it's more about how you can look after your gut. And that in turn is based on conversations with some of the world's leading specialists, microbiome specialists.

So what I do in these books is I give you 40 or 50 scientific references. You will see a lot of endorsements from scientists including one or two Nobel Prize winners.

If they are fad diets, they are well supported by the scientific community.

Can't people just eat healthily and exercise?

Unfortunately, when people say eat healthy and exercise that doesn't mean anything.

It's like saying the way you win at footy is by scoring more points than the other side. It's true, but it's not a very healthy or helpful way of dealing with life.

You actually need to know what healthy means. So once upon a time healthy meant low fat, now we know that's almost certainly not true.

What is healthy now is probably the Mediterranean diet. Well what is the Mediterranean diet?

If you actually look at the science, what scientists describe as the Mediterranean diet is completely different to what, for example, the Department of Health in the UK would describe as one, because the Department of Health in the UK still describes the low fat diet, which has been tested and tested and tested to death.

Same is true of exercise. Yes, exercise is good for you, but what sort of exercises?

You need to do heart and lungs but you also need to do strength, and you absolutely have to put a bit of oomph into it, because just jogging along or indeed just going for a walk is not going to do a huge amount of good.

This is your fourth book, did the first three not work?

The first three worked brilliantly. They're extensions, they're for different things.

So the 5:2 diet was a kind of a starter out the gate. It was kind of intended for anyone who was a bit overweight and wanted to lose some weight and generally improve themselves.

The Fast Diet was obviously completely different, it was about what is the optimal way of exercising to get the most benefit in the least amount of time.

The Blood Sugar diet was much more aimed at people who had type 2 diabetes or who had pre-diabetes.

Clever Guts is about something different. Clever Guts is about how to improve your gut bacteria so they work with you rather than against you.

Are you qualified to write these diet books?

I did a degree at Oxford in politics, philosophy and economics and I was a banker.

Then I was a doctor, then I was doing psychiatry and I went into television.

The paleo diet is based on the notion that our bodies have not evolved to cope with our modern diet, but is it nutritionally sound?

Indeed, I am not a nutritionist and indeed at medical school, like most doctors, I learnt almost nothing about nutrition.

My education in nutrition began pretty much five or six years ago.

The things that qualify me to do so are, I suppose, partly I do it on myself. And partly I get access thanks to my reputation to all the world-leading experts.

So none of these books are based on my original research, they are based on the work of people who have been in the field for a decade, sometimes more, and they've very generously shared their time.

So they know what I'm doing, I'm not stealing their work, and they endorse it.

Do you test these diets on yourself?

Absolutely. So the reason I did the 5:2 diet in the first place is because I discovered I was a type 2 diabetic.

And I didn't want to start medication, which is what my doctor was offering me, so I went and looked for alternatives.

I came across intermittent fasting, I made a film about it with myself as the subject. I lost 10 kilos, reversed my type 2 diabetes and that was five years ago.

With Clever Guts diet, my freezer is stuffed with poo samples.

It's gross, and I send them off to be analysed.

So these days you can get your microbiome analysed — your poo analysed — within a few weeks.

Topics: diet-and-nutrition, health, arts-and-entertainment, australia