Doctor Tim Spector: The Shocking New Truth About Weight Loss, Calories & Diets!

**Steven Bartlett** (0:00)
Exercise doesn't help weight loss?

**Tim Spector** (0:02)
The reason exercise doesn't work is because… Professor Tim Spector.

**Steven Bartlett** (0:07)
He's an award-winning scientist.

**Tim Spector** (0:11)
And he is ranked in the top 100 of the world's most cited scientists. We're going to be talking about the future of personalized nutrition.

**Steven Bartlett** (0:17)
Many consider you to be the leading expert on gut health and diet. What's your view on the ketogenic diet?

**Tim Spector** (0:23)
Virtually impossible.

**Steven Bartlett** (0:24)
What about vitamins?

**Tim Spector** (0:25)
Waste of money.

**Steven Bartlett** (0:26)
What are the facts around fasting?

**Tim Spector** (0:28)
Oh, dear.

**Steven Bartlett** (0:29)
Oh, shit. What do you mean, oh, dear?

**Tim Spector** (0:31)
The food industry wants you to focus on calorie, fat content, sugar, so you don't have to think about the quality of the food.
There's never been any long-term study showing that calorie counting is an effective way to lose weight and maintain weight loss. This is why I want people to think about food very differently than we have done in the past.

**Steven Bartlett** (0:52)
So what is the cost?

**Tim Spector** (0:55)
Depression and anxiety is intricately linked to the quality of your gut microbes. These are microscopic bugs in our intestines. All of them are able to pump out chemicals that are vital for our body when they're fed the right foods.
The reason we're in this state is we've killed off a lot of our good bugs. I think people don't think of all the positive elements that don't think that you need to build them up.

**Steven Bartlett** (1:17)
God, it's so confusing. You know, when you walk down the aisle in the supermarket, everything is trying to pretend that it's good. So how do I know what is good?

**Tim Spector** (1:24)
You have to.

**Steven Bartlett** (1:36)
Tim, many consider you to be the leading expert on topics relating to gut health and diet and food, et cetera. But how would you describe your own professional academic bio? What is that bio in your own words?

**Tim Spector** (1:54)
It's complicated.
So I've changed form over the years quite a lot, and I'm quite unusual in terms of academic medics, who usually stick very strictly to one specialty all their career and fear to go anywhere else. So I was at medical school, did the usual stuff, then wanted to be a physician, then did rheumatology.

**Steven Bartlett** (2:22)
What's rheumatology?

**Tim Spector** (2:23)
And bones and joints. So that was my subspecialty, if you like.
But I got interested in epidemiology, which is the study of risk factors in populations, where you just look at thousands of people rather than one patient. Really, I switched again to study, because I got really interested in the idea that identical twins should be the same. They're clones, they lived all their life together, all their genes are identical.
What makes them different? Counter to what everyone thought, identical twins often die at different times. They get different diseases, one gets depression, one's fine, all these differences. So that was my sort of conundrum. What makes identical twins different when they've lived the same lives? It was only through this sort of search to find this out that I looked at the gut microbes in twins and found they were different. And that really scientifically took me onto this whole new path. From there, I made this sort of leap into nutrition to say, well, now we've discovered this whole new science, all this stuff we got wrong about nutrition suddenly makes sense. So now I would say I'm an epidemiologist who's really specializing in nutrition and gut health and trying to change the way people think about food.

**Steven Bartlett** (3:58)
That was a brilliant summary of your career and academic background.
As a muggle like me, that's really new to many of these topics. What I understand is the study of epidemiology is the study of the genetic root causes of disease.

**Tim Spector** (4:13)
Not just genetics, any root cause of disease. The people studying COVID were all epidemiologists tracking a disease, trying to work out who's getting it, when it's coming back, how common it is, all these basic things in populations at a big population level.

**Steven Bartlett** (4:33)
You've also written 800 articles, more than 800 articles, on this subject matter.
In 2014, you set up the British Gut Microbiome Project, and you've written five books on these subject matters. I've read two of them that are sat in front of me here.
I'm really intrigued by the personal story as well, because writing these books and doing all the work you've done is a lot. It's a lot of work. It requires a lot of drive. This particular book, you said it took almost six years to finish. What is the personal drive behind that? What is driving you to pursue this subject matter?