Need surgery? Time to cut your calories

SLIM PICKINGS: A sample of what an 800 calorie diet looks like.
SLIM PICKINGS: A sample of what an 800 calorie diet looks like.

Strict low-calorie diets are standard procedure leading up to weight-loss surgery but they could become an option for all overweight surgical patients as hospitals struggle to deal with an increasing number of fat patients.

For weeks before going under the knife, obese patients who want publicly funded bariatric surgery need to stick to a very low-calorie, rapid-weight-loss plan. This 800-calorie diet involves a couple of high-protein shakes each day, as well as a small amount of low-calorie fruit or vegetables for variety. Some patients do the diet without the shakes, and some who make it through the three-week plan lose 5kg. But others don't.

For bariatric patients, the diet is designed to shrink the size of the liver and reduce the risk of complications during surgery, as well as to prove they are serious about losing weight.

Currently discussions are underway between Auckland DHB specialist anaesthetist Dick Ongley and other health experts on ways to help patients with an elevated BMI lose weight prior to other surgeries. One option could be a low-calorie diet like bariatric patients undergo.

Dealing with obesity has become an increasingly large part of Ongley's job. Obese patients needed extra resources and focus from medical staff because they have increased risk factors during surgery, and can face a raft of post-operative complications.

Ongely assesses patients with high body mass index (BMI) for mobility, potential heart failure "and we also look at their ability to lie flat". Other problems centre on getting intravenous access through well-padded limbs and safely securing airways during anaesthesia.

Ongley said at least a third of his patients needed this type of care, a situation which had worsened since he began practising in his field in the early 2000s. "It is just part of the job, perhaps it is just one of the challenges. We have become much better at anaesthetising people with an elevated BMI but it does take a lot of resources to do so."

The proportion of New Zealand adults considered overweight has risen to 66 per cent - an estimated 2.2 million people, including 960,000 who were obese.

Ongley said sometimes the anaesthetic assessment was the first time the patient had been confronted with the issue of their weight. "The first thing to recognise is that it is a problem. We need to bring it into society's consciousness. We are very good at addressing smoking and alcohol but BMI has been a very uncomfortable issue for many doctors."

Middlemore general surgeon Richard Babor said every patient who underwent a laproscopic sleeve gastrectomy, a procedure to remove most of the stomach and shape the remainder into a tube or "sleeve", needed to show they were committed to weight loss.

Babor said the diet often led to 4-5kg of weight loss, often on a product called Optifast, a low-calorie protein shake. "They are allowed to have water and other zero-calorie liquid with it. In the evening, for a bit of variety, they are allowed very low-calorie vegetables or fruit. Not things like potato but things like tomatoes and lettuce. They can survive on it because they have got all the vitamins and minerals they need."

Babor said a diet this strict was only tolerable for a short period of time. "Some people can't, they just can't, it's too hard. Obviously we can't drive round to their house and make sure they take their dogs for a walk every day or check their fridge for some cheesecake."

There are about 150 of the publicly funded procedures performed each year in Middlemore. Last year the government funded a record 421 bariatric surgical procedures, each costing between $17,000 and $35,000, more than double the number six years ago.

Some people could do the diet with real food but the protein-shake diet made it easier and more structured, Babor said.

"You do have to conform to a certain lifestyle choice, you can't just have the surgery and everything is sorted, but you still have to exercise and eat reasonable food."

He said the post-operative results were often very successful, with patients losing a lot of their excess weight. "Part of the job is making sure we aren't doing something that's a complete waste of time."

Sunday Star Times