Ask the doctor - diet bars and diarrhoea

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I’ve been successfully losing weight by having a meal replacement shake at lunchtime. Whenever I eat a diet bar, however, I get diarrhoea. Is this anything to worry about?

Some diet bars are sweetened with sugar alcohols, such as sorbitol, lactitol, xylitol and maltitol. These are used as they are not significantly absorbed, do not cause blood-glucose swings that can trigger hunger, and are relatively low in calories. Different people have different sensitivity to sugar alcohols. Some can tolerate a high dose, while others have a low tolerance and just a bite or two of a low-GI diet bar can have a laxative effect. For people prone to sluggish bowels this is, of course, a welcome bonus! Most of us have a ‘normal’ level of tolerance however, and will not notice a laxative effect at usual recommended intakes.
Dr Sarah Brewer, Prima (Oct 11)

I work full time and also look after children and elderly parents, so even though I’d love to diet and exercise more I never seem to have time. The quick fix of achieving a flat tummy through laser liposuction caught my eye recently – is it as good as it sounds?

I can completely understand the pressures on your life (I suffer them all myself!). However, removal of fat below the skin has absolutely no impact on your physical health. The fat that does the real damage in terms of increasing your risk of diabetes and heart disease, for example, is deep inside your stomach cavity. Liposuction won’t reduce the risk of obesity-related cancer either – there is no alternative to a healthy lifestyle to cut these risks. For some people who are not overweight but have love handles, lower tummy bulge or cellulite that remain even when they lose weight, surgery may offer cosmetic (only) benefits. There are many different procedures, including traditional liposuction (dissolving fat cells and sucking them out) and LipoSculpt (using ultrasound to break down fat cells), but they’re not available on the NHS. If you are seriously thinking of going ahead, choose a surgeon who’s a member of the British Association of Aesthetic Plastic Surgeons.
Dr Sarah Jarvis, Good Housekeeping (Aug 11)

My 22-year-old son is 5ft 11in, weighs 91⁄2st and desperately wants to gain weight. He has joined a gym, and after eating five bananas, six eggs and half a chicken every day – plus a muscle-building powder – he put on 51⁄2lb in a week, but feels bloated. Is his diet excessive?

Sudden diet changes can lead to problems with constipation and fluid gain, which might account for his symptoms. He needs to ensure he gets at least five different fruit and vegetables per day. Protein powders can be helpful – blend vanilla flavour Sci-MX Breakfast Shake or Gradual Release Protein Shake (£27.99 for 1kg from www.scimx.co.uk) with fresh blueberries, raspberries or strawberries. Pulses supply protein, as does fish – serve them with broccoli, sweetcorn, sweet potato and green beans. Add carbohydrates in the form of oats, brown rice and wholewheat pasta. And tell him to drink plenty of fluids.
Dr Sarah Brewer, Prima (May 11)

I need to lose weight. My sister has lost two stone with the Jenny Craig diet, but I don’t want to invest in it if I’m only going to put the weight back on. Is it worth it?

The Jenny Craig diet (jennycraig.co.uk) uses a combination of prepared foods and ongoing counselling. The Go Lower diet (golower.co.uk) uses similar principles. Both recognise that our trigger points for overeating are very individual. Normally, I don’t recommend diets where meals are prepared for you, as keeping weight off long term depends on changing unhealthy eating patterns for good. However, for many of my patients portion size is a real issue. With these diets, you spend a couple of weeks eating only portion-controlled meals and learn to introduce healthy foods you cook yourself. And the one-to-one counselling does seem to help set you up to maintain your weight loss long term – often the hardest bit.

Dr Sarah Jarvis, Good Housekeeping (Oct 10)

My brother is hugely overweight and has developed diabetes. His GP has agreed to refer him for gastric banding, but is this necessary – or safe>

For many people who have tried and failed with all the alternatives, surgery can bring huge benefits. Bypass surgery can produce more dramatic results, but banding is the safest option. In fact, serious complications are much less common than you might think – and dying is three times less likely after gastric banding than after a procedure like gallbladder removal. This also needs to be balanced against the huge risks to health of morbid obesity. Gastric banding is done by keyhole surgery and places a band part-way down the stomach to reduce it in size. Solid foods take a long time to be digested – this means you feel full much sooner and for longer. Some people can ‘cheat’ after gastric banding by taking high-calorie liquid foods that slip through the band easily, but it really works for many.

Dr Sarah Jarvis, Good Housekeeping (Sept 10)

My daughter is 10, and I'm worried because I know she's overweight. I've tried everything I can think of to encourage her to exercise and eat healthily, but it just doesn't work. How else can I help her?

I do sympathise - children live in a world full of temptation, with too few incentives to exercise or eat healthily. But you're right to worry about her weight - children in the UK are getting fatter even faster than adults. And being overweight can cause all sorts of physical complications in the long term. Mind, Exercise, Nutrition... Do it! (MEND) is a practical, hands-on programme of activities for 2-13-year-olds and their families. It teaches healthy lifestyle habits in a supportive environment with other children. There are 350 sites across the UK, and your GP can refer your daughter - or you can refer her directly by calling 0800 230 0263 or visiting mendcentral.org.

Dr Sarah Jarvis, Good Housekeeping (Jul 10)

Goji berries for weight loss?

I've seen goji berries advertised for weight loss, but I thought they were mainly a source of antioxidants. Can they really help me lose weight?

Although goji berries are often marketed as a weight-loss supplement, I have not found any reliable evidence that they are effective for this use. In fact, one of the few studies that have been carried out found that people taking goji berry extracts did not show any significant changes in body weight, body mass index, blood pressure, pulse rate or visual acuity compared with inactive placebos. They are a great source of antioxidants however, and the same trial did find that they reduced fatigue and feelings of stress in those taking them, with increased feelings of wellbeing.

Dr Sarah Brewer, Prima (May 10)

I took the weight-loss drug Reductil for six months last year and shed almost two stone. Now I hear it's been taken off the market because it's dangerous. Do I need to worry?

Until recently, Reductil was one of three weight-loss drugs that GPs could prescribe. Another, Acomplia, has been withdrawn because of concerns it increased the risk of depression. This year, the body that oversees medicines' safety reviewed evidence that Reductil might increase your risk of heart disease, and concluded the risks were too great to continue to allow people to take it. That doesn't mean it's unsafe for everyone, and if you have stopped it you have nothing to fear. People still taking it, however, should consult their GPs. The third weight-loss drug, Orlistat - sold through pharmacists at a lower dose - is still available and there are no significant safety concerns with it.

Dr Sarah Jarvis, Good Housekeeping (May 10)

Will shoes really tone me up?

Do shoes that claim to give you a gym workout just by wearing them really work?

Shoes such as MBTs, Reebok EasyTone, FitFlop and Skechers Shape-Ups create a natural instability that make muscles work extra hard with each step you take. Research at the University of Delaware found that EasyTone increases buttock muscle use by 28 per cent, while Shape Ups claim 40 per cent improvement after six weeks of use. You are unlikely to see a long-term improvement just from your footwear, but in combination with a good diet and exercise program you should feel more toned. For details, visit fitflop.com and lovethoseshoes.com. 

Dr Sarah Brewer, Prima (Jan 10)

My eight-year-old girl seems unusually overweight, unlike her older siblings. As she does not eat too many treats, could it be glandular?

Hormonal imbalances, such as hypothyroidism or Cushing's syndrome, can cause childhood obesity - but it's very rare. However, obesity is becoming more common as kids are eating more sugary and fatty foods and taking less exercise. In 2004, 14 per cent of boys and 17 per cent of girls, aged two to 15, were estimated to be obese and this is increasing. A culture of watching hours of TV or playing computer games means that many take little exercise. But you must tackle the problem, as overweight children are more likely to develop heart disease, diabetes and some cancers. It isn't easy getting children to follow a good diet - so do it gradually, encouraging her to eat healthier foods and take part in regular sports. But if you're still convinced that her lifestyle isn't responsible for the weight gain, you must talk to your GP.

Dr Louise Selby, SHE (Dec 09)

I'm losing weight...

I've been feeling more tired than usual, sweating a lot, and I've lost 5kg. I'm really pleased with the weight loss, but wonder if I have an overactive thyroid. If so, I don't really want it treated, in case I put the weight back on.

These symptoms ring alarm bells as they can be due to a number of problems, including undiagnosed diabetes, hidden infection or an overactive thyroid gland. Make an appointment with your doctor straight away to have your blood-glucose levels measured, as you may need urgent treatment. Don't delay. Discuss your concerns about gaining the weight again with your doctor, so that any treatment can be monitored, but don't put off seeking help.

Dr Sarah Brewer, Prima (Feb 09)

A friend has been taking a weight loss drug called Xenical and has lost several stone. I'm keen to try it, but are these drugs safe?

Xenical, a popular aid to weight loss, can only be prescribed by a doctor. On the NHS it can be prescribed for people with a BMI of 30 or more (20-25 is normal) or 28 if there are other risk factors, such as type 2 diabetes, hypertension or high cholesterol.

Xenical stops your body absorbing fats from your diet, but this makes it unpleasant to eat fats as they have nowhere to go except out through your bowels, which leads to tummy cramps, wind and loose, floaty stools. So it's best used in conjunction with a low-fat, weight-reducing diet. If you stick to the diet, you won't suffer any side effects, but if you lapse, you'll regret it later!

If taken long term, your body can become deficient in the fat-soluble vitamins A, D, E and K, so a vitamin supplement would be recommended. In order to continue Xenical beyond 12 weeks you must have achieved at least five per cent weight loss from the start of treatment. To take it beyond six months there must be at least 10 per cent weight loss.

Dr Louise Selby, SHE (Dec 08)

Diet drug

I’ve been prescribed Rimonabant for six months to help me lose weight, but I feel miserable and I’ve hardly lost any weight. Is this really a miracle drug?

Rimonabant, which is sold under the brand name Acomplia, is an appetite suppressant that should help you stick to a low-calorie diet. It is not, however, a miracle pill and most people lose only a small amount of weight while they’re taking it. It sounds to me that this treatment isn’t right for you and, whether it is the drug that is making you miserable or its failure to work, I think that you should probably come off it. Talk through alternative options with your GP. But remember that there is no such thing as a quick fix in the fight against obesity. A healthy diet plan combined with regular fat-burning exercise is your best bet and, with a little willpower and some expert advice, there is no reason why you should not be able to reach your goal. You’ll find plenty of helpful tips on losing weight at weightconcern.com.

Dr Louise Selby, SHE 

Weight gain and the Pill

I’ve been in a new relationship for the last six months. To begin with we used condoms, but then I decided it would be a good idea if I went back on the contraceptive pill as I didn’t want to take any chances. However, since I’ve been taking it, my weight has gone up by over half a stone. I’m 36. Would swapping to another form of contraceptive help?

It's true that you can put on a few pounds when taking the combined contraceptive pill. However, have you considered whether it's your new relationship that's to blame? Many women start taking the Pill because they've met a new partner. But just think about the early stages of a relationship - you've probably been going out for more meals and cooking more elaborate recipes for you both, and you may also have less time to exercise. So before you automatically blame the Pill, have a careful look at your changed lifestyle.

Dr Sarah Jarvis, Good Housekeeping

Contraceptive injections and weight gain

Last year, I used the depot contraceptive injection for nine months. At first, I noticed that I’d put on a few pounds, but then my weight suddenly started to balloon. I stopped using this form of contraception nine months ago, but my weight is still going up. What’s causing it and what can I do to stop it?

While excessive weight gain with the depot (slow-release) form of contraception isn't common, it can happen. And while it's normal to put on some weight - the average is about 5½lb a year - it can be much more than this for a few women. The fact that your weight has continued to go up, however, even though you're no longer using it, suggests that there might be another cause, such as an underactive thyroid gland, that needs to be investigated. I suggest that you make an appointment to see your GP and ask if you need to have a blood test to rule this out.

Dr Sarah Jarvis, Good Housekeeping

Weight loss

Recently I switched to a healthier diet, and lost about half a stone. But my practice nurse says I’m a little underweight. Is it dangerous?

It depends just how underweight you are. Being very underweight (usually measured by a body mass index - BMI - of under 17) can increase the risk of osteoporosis, or thinning of the bones. But if you're within seven pounds of the ideal range, you're highly unlikely to have problems. Unless you are seriously underweight, low weight is, generally, much healthier than being obese.

Dr Sarah Jarvis, Good Housekeeping

Can a pill help me lose weight?

According to an article I read recently, there is a new slimming drug you can buy over the counter. I've been trying to lose weight for a year without success. I'm too busy running my own company to spend any time in the gym and I often eat ready-made meals, which doesn't help. How do I get hold of this drug – and is it safe?

You are referring to the Alli tablet made by GlaxoSmithKline. It's expected to be approved for use in the UK next year, but it's not a wonder drug – it's only effective when combined with a healthy diet and willpower, and side effects include diarrhoea. Trials suggest that once people stop taking the drug they regain all the lost weight.

Being overweight means you're at risk from health problems including diabetes, heart disease and some cancers, so it's important to make a long-term healthy-eating plan a priority. It is difficult, but if you're organised and committed, it is possible.

Cut out ready-made meals and junk food and stick to a balanced diet with fresh fruit and vegetables. Think about joining a dieting group – it's easier when others are spurring you on. Regular brisk walking will help control your weight – and reduce stress! For further advice, visit weightconcern.org.uk.

Dr Louise Selby, SHE

Help me with my diet!

I have irritable bowel syndrome and need to lose weight. How do I find a qualified dietician for expert advice?

The term dietician is protected by the Health Professions Council (HPC) in the UK, and only people who are properly qualified can register with the HPC. Your GP can refer you to a dietician or you can contact the HPC (hpc-uk.org or 0845 300 4472) to ensure your dietician is registered.

Dr Sarah Brewer, Prima

My waist is thickening

I drink lots of water during the day, but have noticed that I’m gaining weight around my waist. I only have one kidney. Could this be the reason?

Drinking fluids will not cause weight gain in the form of fat around the middle, although it can cause fluid accumulation – for example, around the ankles. As you are concerned, do see your doctor to check your kidney function. Weight gain around the middle is usually due to excess fat, and ‘middle-age spread’ is a possibility. The good news is that fat stored on the abdomen seems to be easier to shift through diet and exercise than fat stored on the hips.

Dr Sarah Brewer, Prima

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The answers to specific problems may not apply to everyone and are not substitutes for professional medical advice. If you're worried, see your GP. For more information, visit netdoctor.co.uk