Wednesday, March 20, 2013

Want to slim AND repair creaky knees? Have a milkshake (?)

Nothing works for long

Liquid diets have had an image problem — the idea of losing weight by mixing sachets of powder into meal replacement milkshakes or soups makes dietitians very unhappy.  They worry that losing weight too quickly could be bad for you, and such plans don’t teach you how to eat healthily afterwards.

Indeed, many people do quickly put all the weight back on.

And then there are the pyramid-selling techniques behind some of these liquid diets, which have caused doctors to be especially cautious about making use of them.

But that poor image could be due a rethink following compelling new research suggesting low-calorie liquid diets can tackle obesity and reverse type 2 diabetes.

And it was backed by an editorial in the British Journal of General Practice last month.

For three months, all your food comes in the form of a nutritionally balanced drink. Either fruit or savoury-flavoured, it supplies 800 calories a day.

‘It’s a bit of a shock for the patients to start with,’ says Mahri Swanson, the practice nurse at the surgery. She adds: ‘These are people who could have been eating 3,000-4,000 calories a day.

‘For the first few days they are really hungry. But, surprisingly, most quite quickly say it’s OK, and within a week aren’t craving food.’

According to the February issue of the British Journal of General Practice, about 30 per cent of the 90 people taking part lost 15 to 20 kilos and kept it off for a year with a lot of support.

Several Scottish health authorities are planning to make liquid diets available through GPs  as a result.

Professor Mike Lean, chair of human nutrition at Glasgow University and a lead researcher on the trial, is having discussions with Diabetes UK about funding for a larger controlled trial of 200 people to properly test the  diabetic benefit.

‘The rising number of people who are obese or diabetic is going to cost billions,’ says Professor Tony Leeds, an obesity specialist who runs a clinic at the Central Middlesex Hospital in London and has been treating patients with liquid diets for years.

‘If these results are repeated, the savings could be huge.’

Indeed, in Denmark a liquid diet is about to become the first-line treatment for people with osteoarthritis of the knee.

This follows a study which found that when 175 osteoarthritis patients were put on a liquid diet they not only lost a lot of weight, nearly all of which was fat, but more than 60 per cent also showed significant improvement in pain and disability.

‘Until a few years ago all that was on offer for these patients was painkillers and advice to lose weight that rarely worked for long,’ says Professor Henning Bliddal, a rheumatologist at Frederiksberg Hospital who led the study.

‘Osteoarthritis normally makes bones weaker by reducing bone mineral density.

'But the bones of patients on the liquid diet improve, possibly because it contains the recommended daily allowance for all amino acids, fatty acids vitamins and minerals.

'This means they get extra vitamin D, which is vital for building bones.

‘About ten per cent of people over 55 have bad knees and are overweight, and the diet has changed the way we treat them,’ adds Professor Bliddal, who is running a trial to test the possibility that it can improve the structure of damaged cartilage in the knee.

The Danish study, published in the European Journal of Clinical Nutrition in 2011, concluded that the liquid diet was ‘effective and safe’.

In fact, despite concerns that a rapid drop in calories might be bad for you, emerging evidence suggests it may lower cholesterol levels.

Some researchers have even suggested it might even reduce asthma symptoms.

But whatever calorie restriction regimen — diet or liquid diet — it’s clear that a supportive and effective follow-up programme to make sure that the weight stays off is vital.

This has been a key part of the Scottish trial.

And it’s the special focus of the Rotherham Institute for Obesity, which over the past three years has helped the local population of 250,000 lose 17 tons between them — and halved the weight loss surgery rate in the first year (30 fewer patients have had the surgery, saving around £300,000).

The institute takes 2,000 referrals a year.

‘Our team of dietitians, fitness experts, psychologists and cooks make sure they have a good chance that any weight they have lost stays off,’ says Dr Matthew Capehorn, who heads the scheme and is also clinical director of the National Obesity Forum.

Under official guidelines from the National Institute for Health and Clinical Excellence (NICE), low-calorie diets are available on the NHS for people ‘who are obese and have reached a plateau in weight loss’.

The hope is that the new evidence will give GPs more confidence to use them.


Taking Vitamin D in pregnancy 'does not help babies develop stronger bones'

Levels of vitamin D in pregnant women may not affect the baby’s bone health - contrary to official advice, say scientists.

They found no link between a mother’s levels of the vitamin while carrying the child, and the latter’s bone health at the age of 10.

Current NHS guidance says all pregnant and breastfeeding women should take a 10 microgram vitamin D supplement every day, because it is believed to help build stronger bones in their offspring.

Professor Debbie Lawlor, who led the Children of the 90s study at Bristol University, said there was ‘no strong evidence’ that pregnant women should be taking vitamin D supplements.’

But other experts said some groups of women such as those getting little sunlight and the obese were more at risk of low vitamin D stores and they should still be encouraged to do so.

The study published in The Lancet medical journal assessed vitamin D levels in 3960 women throughout their pregnancy.

The bone mineral content (BMC), a measure of bone health, of their child was then assessed at an average age of 9.9 years.

Researchers measured vitamin D levels at all stages of pregnancy.

Levels were higher in summer months and lower among non-white mothers and those who smoked during pregnancy, but overall there was no significant link between a mother’s vitamin D levels and her child’s BMC.

Dr Tony Falconer, President of the Royal College of Obstetricians and Gynaecologists, said ‘We know that Vitamin D regulates the amount of calcium in the body, which helps to keep bones and teeth healthy, and low levels have been associated with problems relating to the baby’s bone formation and a higher risk of diseases such as rickets and osteoporosis in later life.

‘Some women are more at risk of having low vitamin D levels, these women include those of south Asian, black African, black Caribbean, or Middle Eastern origin, women who have limited exposure to sunlight, obese women (pre-pregnancy BMI >30) and those who eat a diet low in vitamin D. It is particularly important these women get their required dose.

‘As healthcare professionals, it is our role to reinforce the importance for proper diet and nutrition during pregnancy and throughout a woman’s lifespan.

'It is important that at-risk women are informed, at their first antenatal booking, of the importance of adequate vitamin D during pregnancy and after, to maintain their own and their baby’s health.

‘Further research is needed to look at vitamin supplementation including potential benefits, harms and optimal dosing.’


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