Live webchat with BBC What's The Right Diet For You? presenter Professor Susan Jebb OBE Tuesday 13 January from 2 to 3pm

[TraceyEMumsnet]

According to the BBC 11 million of us are on a diet in Britain today, yet the vast majority will fail. So what's the best way to lose weight successfully - and keep it off?

What's The Right Diet For You?, a 3-part Horizon special on BBC Two airing this week, will investigate how differences in our biochemistry, psychology and genes may affect our weight.

The programme follows 75 overweight volunteers from across the UK, who will be put on personalised diets to explore three possible causes of overeating: genes; gut hormones; and emotion-related eating. The experiment is led by a team of world-class scientists, one of whom will be joining us tomorrow for a webchat.

Susan Jebb OBE is Professor of Diet and Population Health at Oxford University. She is a nutrition scientist with 25 years' experience of research on preventing and treating obesity and diet-related ill health.

Can science succeed where other diets have failed? Interested in science tips and general weight loss advice? Put your questions to Professor Susan Jebb on Tuesday 13 January between 2 and 3pm, or post your questions in advance on this thread.

You can find out more about the programme here.

1. Reading the online Horizon test, it recommends for Imtermittent Fasting that fast days have 600-800 cals. There have been a large number of IF research and human trials which settled on 25% TDEE, approximated by 500 cals women / 600 cals men. Varady in particular examined different %TDEE for fast days and found 25% to be the optimal solution to combine weight loss with muscle retention.

Why did you specify the higher cals for fast days ? Sustainability / psychological reasons ?

2. There is a great difference in body composition and hormones between men and women, but the online Horizon test doesn't ask gender.
   Are you investigating any different recommendations / test algorithm for men / women

3. Are you investigating different recommendations at different ages ? In particular young women and post-meno respond differently to diets.

Test

After many years of eating disorders and yo yo weight problems I changed my attitude/eating habits about 20 years ago. I enjoy being a vegetarian as I love fruit, vegetables, seeds, nuts and dairy produce. I don't eat any processed food except for wholemeal bread. However, I bake and make my own chocolates only using quality ingredients. My problem is I have a very sweet tooth and wonder if this is harming my health?

Hi everyone

I'm really pleased so many of you have enjoyed the programme and I can see some great questions here. I'm looking forward to answering as many of them as I can.

Susan

@MelanieCheeks

Did the 5:2ers on the show have 2 consecutive low calorie days?

Hi MelanieCheeks

We recommend two consecutive days of dieting if you can because with the low carb approach on these days ketones build up in the blood stream which act as a natural appetite suppressant. Our participants told us that the second day was much easier than the first and strongly recommend this approach. If you can’t do two consecutive days better to do them separately rather than not at all.

I'm interested in your answer to BigChocFrenzy's question about intermittant fasting. I'd also like to to know how/where I can find out more about your version of this diet.

@mollister

I have just done your customised dieting test online and have come out with roughly the same score for each type of eater! 33, 33, 34, I know it doesn't add to 100 but it must round up/down. So what should I do? a bit of each? The one that has the half mark higher?

Hi Mollister

Thanks for raising this. I suspect many people will find the same thing in the sense we are only testing three specific factors leading to weight gain. There will be many more and you may fall into another group more specifically. The key point of the programme is that we want people to think about their own eating behaviour and consider which diet might be best for them rather than just following the latest diet trend.

In the second episode I hope everyone will find lots of genetic tips, based on science, which can help whatever diet you are following.

Should I avoid the gym on a fast day?

I'm interested in the differences between the groups' physical results (hormones and genes) and their psychological results. Did you select participants who didn't overlap between the groups? Will the team be publishing the details of the programme so that some of us geeks can pore over them?

@scousadelic

I am obese, my BMI is stupidly high and I have tried every diet and every support known yet relapsed time after time leading to a weight gain each time. I would love better support and more accurate, definitive dietary advice but am not sure how we know who we can trust.

Many diet groups have vested interests in processed foods (Weight Watchers and Atkins spring to mind) and many advisors and experts, yourself included, have links to food and weight loss groups. I know funding has to come from somewhere but my question is:
How do we know who we can trust and who is representing the interests of companies paying them?

Hello Scousadelic

I can appreciate your concern and you will need to make your own judgement. I do not do any personal work for any food companies. Any research we do funded by companies is governed by very strict contracts set out by the unit to protect our independence. So for example companies have to agree that we can publish our results whatever they show and however we wish. This means we report things that don't work and those that do.

@twixxy

165cm 71kg - according to BMI charts I need to lose up to 5kg (best part of a stone) But I'm a size 12, fit (exercise at least 4-5 times a week) and a GP friend told me not to lose weight as I would "look old". So do I? Don't I? I've (personally) found the only way that works for me is to eat less and move more. Is this one you approve of?

Hi Twixxy

Great to hear about you physical activity which is really important for overall good health. Your BMI is only just over 25. That's the point at which I tend to encourage people to mostly focus on eating a healthy diet and to take care not to gain weight rather than worrying too much about losing it.

@26Point2Miles

Don't you rate exercise/movement as important? Or just what we put in our mouths?

I lost 5 stone low carbing... I'm halfway through losing 2 more and m low carbing...all with a bit of paleo style thrown in

Hi 26Point26Miles

Yes, exercise is really important and you will see more about this in the next two episodes. You will need to do an awful lot of exercise to lose weight, but it's especially helpful to keeping the wright off in the long term. And its a great way to improve your health overall, which really is the ultimate aim.

i did the test and was not in any of the categories.

My problem is that I'm not hungry at all..... even feeling nauseous at the thought of food.... then suddenly I'm ravenous and will eat to stop shaking.

for instance I havent had anything to eat today. Im not even hungry, but i will have a normal portion on a small plate for my tea. I have drank two cups of tea with sucralose sweentner.

im 5'3 and weigh 12 stone.

Im a CM and run around after children all day, but come 6 o'clock im asleep on the sofa. I sleep for a few hours then will potter for 2 hours and go to bed at 10. I get up at 6.30

I know what im doing wrong. I should eat three meals a day, but i would be sick if i ate too early.

I thought your programme might be a solution but i dont fit your categories

@SnowyMouse

I pretty much have to rely on ready meals as I am severely disabled and carers aren't with me long enough to prepare food from scratch. How can I lose weight? (exercise is also difficult).

Hello

Oh, I am sorry that it is especially hard for you, but please don't despair the range of ready meals today is better than ever before and more have lots of fresh ingredients. Use food labels to choose the healthier options and always serve with extra veg. Frozen veg is often the most convenient.

I should also point out that i have complex medical issues and hormonal imbalances but have no idea how to balance them again

@Lovecat

My results were Constant Craver yet I have struggled to lose weight on a 5:2 regime. The only diet I ever lost weight on and kept it off with is low carbing, but after having DD I've never been able to get back on and keep it up for more than a few weeks.

There didn't seem to be an answer in the questionnaire for what is my worst problem, which is eating when I'm bored. I'm not an emotional eater at all, and if I'm busy, I hardly ever think about food - yet if I've got nothing to do I suddenly want to eat ALL the food! Is there a type for that...?

Hi Lovecat

Our version of intermittent dieting involves low carb eating on the two dieting days, which is a way of combining two different diet strategies. But if low carb dieting lone works for you that's great. Episode three of the series will focus on keeping the weight off so I hope it will have some useful tips for you.

@Madeyemoodysmum

I'm same as Lovecat but did loose 21lb on 5:2.

I kept it off but still struggle with boredom eating.

Hello

Many people will recognise the boredom eating syndrome, and identify it is the first step to solving it. Now you need to make a plan for what you will do instead at these times, to replace eating. If you practice this it will gradually become a habit. Check out some of the advice for emotional eaters which explores the catch it, check it, change it strategy.

www.bbc.co.uk/programmes/articles/CKQpPBGrcYkWlMcb7NYtbq/what-is-cognitive-behavioural-therapy-and-how-can-it-help

Do you have any particular advice for short people ? I am 5ft and I think that my daily calorie intake should be low and have struggled to lose weight on calorie controlled diets as I don't think the recommended calorie intake is low enough for a short person, but I have not found any recommendations specifically on this. For example, I went on a 1200 calorie diet for 3 weeks to the letter, I measured everything and did not lose a lb.

I have lost weight successfully with low carb, but after having another child and little sleep have struggled to keep this up. It is hard to keep to low carb when your children are eating carbs and you are surrounded by the stuff!

@irishe

I have been insulin dependent diabetic for 3 years and have put on a considerable amount of weight in this time. My diabetic consultant has told me it is hard to lose weight because of how the insulin converts in the body. I don't really understand this to be honest. My highest score was constant craver but had high feaster as well. Would you recommend IF for a diabetic? I think I would feel dizzy on the low calorie days - am prone to this anyway.

Hi Irishe

Anyone with a specific medical condition should discuss any dietary changes with their doctor or dietitian. For people with diabetes but not on insulin it may be ok to follow an intermittent diet but your medication may need adjusting. Please speak to your doctor first.

I was quite surprised that the 5:2 was recommended for Constant Cravers, as I would have thought they would be the group most likely to overeat on non-fast days (my personal undoing with this approach). Do you address this in eps 2&3 of the programme? was it a problem for members of that group?

@herecomesthsun

I'm also sceptical re the science of separating the different groups. There doesn't seem to be a control group. The mere fact of being on a weight loss programme on national TV must be quite motivating to lose weight, whichever diet you choose. All the groups are going to get quite a lot of emotional support and encouragement, just by being on the programme.

Also, it is relatively much easier to lose weight short term, but very hard to keep it off. My hunch would be that whatever the notional rationale for losing weight, the vast majority will lose a decent amount of weight - but almost everyone will put it all back on in the next year or 2.

Hi Herecomesthesun

You're absolutely right - this isn't a full scientific experiment but it is all grounded in science and it is a way for us to begin to explore the idea of personalised dieting.

@Osmiornica

Low calorie diets don't work - the majority of people lose a bit then put it back on again. So either everyone is weak willed and are not trying hard enough or the low calorie diet doesn't work for lots of people. I find it very hard to believe that all the people that fail at diets are just not trying hard enough.

Do you think that people who fail at diets are weak willed or is there something else at play?

Hello there

I hope one of the things people will appreciate from watching the programme is that for some specific biological reasons some people will find it harder to control their weight - and that includes both losing it and keeping it off.

@Guyropes

If I skip a meal, or eat later than usual, I get horrific migrainous headaches. I then try to cure said headaches by eating. It doesn't work. Does this fit with 'constant craver' picture, which was my result on the test? There is no way I could eat 800 kcal twice a week without getting headaches. Plus I'm not convinced by the genetic argument... Neither parent is overweight. Both my brother and I are bordering on obese, although he is well built and very fit. I am a less fit, but muscular size 16 with a fat tummy. So I have about 15 kilos to lose.

Hi Guyropes

Sorry to hear about your headaches. Often headaches after skipping a meal can come from dehydration. Make sure you really are drinking plenty. But remember too that there are other ways to lose wright and a very low energy approach may not suit you.

Certainly, at my age, I am the same shape as my mother who also struggled with weight. I remember being horribly embarrassed that she took up jogging around the neighbourhood! I am sure genetics play a factor, but how do you understand this?

Also, BMI is not without fault, not accounting for large 'norks' or a large amount of muscles