Nigella Lawson has said that she doesn't like the moral superiority and smugness that sometimes accompanies clean eating.

Speaking at the Cheltenham Literature Festival, the food writer and chef said that while she appreciates the trend for eating healthily, she resents "the moral superiority" that some exert over those who choose to eat more indulgent food.

"What I don't like about clean-eating is that it really seems to be indicative of a view that finds eating dirty, shameful, impure, something to disapprove of or to fear," she said. "It seems a way of not living wholeheartedly.

"I like all food and I don't actually make value judgments. I like really good chips — hand-cut — I like kale, I like steak, I like lemon meringue pie. I love all food that doesn't have to be any one school of belief. 

"I also don't like — some people, not everyone does this — the smugness that goes with it. Everyone is entitled to eat as they wish. I don't mind at all, as long as nobody stops me eating what I want I would never interfere with anyone else's eating patterns. 

"What I don't like is the moral assumptions that go with that. I can see, of course, that there are moral assumptions you could make about being vegetarian or vegan, but I don't really like it when people try and go on diets to be thin and then want to claim moral superiority for it."

"All diets are destined to fail," she added. 

Lawson also revealed that she put off writing her first cookery book, How to Eat, for a long time. "It took me many years not to do it but then I wrote it in six weeks. 28,000 words in one day was my record. But a lot of the words were just 'one carrot'...

"I was so late with it, though. I signed the contract and then found out I was pregnant and then John [Diamond, Lawson's late husband] got ill and things were difficult."

And if she was reluctant to write books about food, she was even more uncertain about being on television. "I resisted TV for a long time and waited until I was 40. I always said 'no' but then I said 'look, if I can do it at home and not scripted, I'll do it.'

Lawson added that she still won't do her cookery shows scripted. "I'm not performing, I'm just being me."