Each week, dietician Professor Ashley Adamson will be offering her own perspective on the programme, and giving us some tips on counting the calories and eating well. Here's her reaction to the first episode...

How did you feel when you first saw Si and Dave’s food dairy?

I was quite pleased because I thought they were honest - it’s really difficult to record everything you eat and drink. It was hugely helped by the fact they also sent me the videos. I could see things that could quite easily be changed; with good advice, support and with their personal commitment I knew they’d be able to lose weight. If they had said that they only ate lettuce leaves and water it would have been difficult to lose weight.

It is not uncommon for people to lack accuracy in their food diaries, there’s what we call ‘Optimistic bias’ where people may tell you what they intend to do in the future rather than what they currently do. With Si and Dave, there was a good base to makes changes and set goals.

How typical is this compared to the average man in the UK?

More than 60% of adults are overweight or obese in the UK [you can take a look at the Department of Health's website for more information]. The Hairy Bikers’ diets were high in fat and they had a quite a lot of alcohol, and I don’t think that’s untypical of men who are overweight. Perhaps they have a bit more money to spend on food than your average man, and they can spend money on good food and good wine. 

People who don’t have that amount of disposable income often eat high-fat food like pies and pasties, which are cheaper but have a very high fat content. What they were both eating was really good quality food but it was still very high in fat and had too much energy (calories).

Why is calorie counting and watching your weight deemed to be a very feminine thing?

In the UK we have as many men overweight as women, but if you go to any of the weight loss groups only about 3-5% membership are men. I think generally food and healthy food is seen as a ‘girlie’ thing.

If you think about the adverts for men’s food - pot noodles, pies and pasties, chip adverts - these are the food adverts that contain men, whereas women appear on screen with low-fat yoghurts, cereals etc. Also, in many households women still have the main responsibility for food.

Perhaps there is not the same pressure on men to stay slim. If a man’s overweight he’s a ‘big’ man, whereas you’re a ‘fat’ woman – there’s not the same social pressure but the health imperative is the same.

How many calories are there in 'healthy' fats? Are these red herrings?

All fats have exactly the same number of calories per gram – all have 9 calories per gram. It doesn’t matter if it’s olive oil (which is monounsaturated fat) or lard (which is saturated fat), the difference is that if you’re trying to lose weight you have to reduce all fats, as all are high in calories.

Monounsaturated fats and polyunsaturated fats are better for us but have the same calories. People can confuse healthy foods with the calorie value of them - health is about much more than just the calories in foods.

There are foods that are labelled as ‘healthy’ and people look at that and think it’s low calorie – but as it may not have been deemed ‘healthy’ because of a lower calorie content this can be confusing. If you are trying to lose weight, look out for the calorie content of foods and don’t be misled by other ‘healthy option’ labels.