GPs are putting more and more effort into treating obesity and its medical complications. The unofficial M&M&M syndrome, where people have the metabolic syndrome plus mechanical complications resulting in poor motivation, often lead to a deteriorating level of health and well being.

So what part does exercise play in improving and perhaps reversing these trends and what help is available in our community to support GPs in managing these problems? This article will point out some exercise strategies that may help and will discuss the newly announced Enhanced Primary Care Medicare Plus program using exercise physiologists (see also article on page 17 about the new Team Care Arrangements).

Not putting on weight in the first place
Early intervention in encouraging people not to put on weight in the first place should always be on GPs’ agenda in their advice to patients. Always remember it is much harder to lose weight than not to put it on initially.

How much physical activity do we need to do to prevent primary weight gain? This obviously depends on caloric intake of food and drink as well as how much incidental activity we get in our occupation and leisure pursuits. The National Physical Activity Guidelines will tell us we need at least 30 minutes of planned activity a day, plus as much incidental activity as possible and more strenuous aerobic activity sometimes if we can. The minimal recommended level of physical activity to promote improvements in health and prevent weight gain is at least 150 minutes a week. More research is currently been done on this and advice may change in the more active direction over time.

Losing weight
Being overweight or obese is a result of an imbalance between energy intake and energy expenditure. To lose weight we can either eat less or increase activity levels. But how much exercise do we need to do to lose weight?

Over six months of intervention many studies have shown that diet plus exercise interventions show the greatest weight loss. Diet alone comes second and exercise alone is by far the least successful with only marginal losses in weight recorded. Typical results are shown in a study by Hagan et al (1) that showed over 12 weeks of intervention in a group of men 11.4% weight loss for diet plus exercise, 8.4% with diet alone and only 0.3% for exercise alone.

However, exercise alone that increases expenditure by 700 kcal/day can be as successful as reducing the diet energy intake by 700Kcal/day. Over three months one study by Ross et al (2) showed that there were comparable weight losses of 7.6kgm between energy restriction and energy expenditure groups respectively. The big catch is that a 90.7kgm individual would need to do brisk walking or equivalent exercise for 1 hour 57 mins per day to expend the extra 700 kcal/day.

A more manageable clinical approach may be to increase exercise expenditure by 350 kcal/day and reduce energy intake by 350 kcal/day, which theoretically should lead to the same result. Some people fail to lose much weight with exercise because of excessive energy intake - it doesn’t take much energy dense food to undo all the good of exercise as many will have discovered.

Weight loss without regain
To look at the longer term success in weight control the National Weight Control Registry (NWCR) was established in 1994 by Dr James Hill et al from the University of Colorado Health Services Centre, Denver, Colorado. The NWCR is the largest ongoing study of individual weight loss maintainers. Research has shown (3) that about 20% of overweight individuals are successful at long term weight loss when defined as losing at least 10% of initial body weight and maintaining the loss for at least one year. The NWCR members have now lost an average of 33kg and maintained the loss for more than five years.

The key to their success has been reported as due to engaging in high levels of physical activity of one hour or more a day, eating a low calorie, low fat diet, eating breakfast, self monitoring weight and maintaining a consistent eating pattern across weekdays and weekends. Continued adherence to diet and exercise strategies, low levels of depression and disinhibition, and medical triggers for weight loss are also associated with long term success. It was also found that weight loss maintenance may get easier over time and the chance of long term success improves after 2-5 years.

Improving insulin sensitivity
Insulin resistance is an important feature in the development of glucose intolerance and type 2 diabetes. Exercise increases post-exercise insulin sensitivity for 48-72 hours. Even in the absence of weight loss insulin sensitivity can be improved, which is helpful for managing type 2 diabetics who may find it hard to lose weight, particularly if they are on insulin, sulphonylureas or troglitazones.

Improving cardio-respiratory fitness
There is growing evidence that physical activity results in improvements in cardiovascular fitness and health outcomes independent of weight loss. Wei et al (4) reported that cardiorespiratory fitness was a significant predictor of CVD and all cause mortality across categories of normal weight, overweight and obese men. Similar findings have been found with women with low levels of cardiorespiratory fitness being a stronger predictor than BMI of all cause mortality. Reducing sedentary lifestyles is a major preventative health strategy for GPs to promote in their practices.

Other health benefits of exercise
There is an increasing body of evidence to support some benefits from exercising and weight loss in helping with pain reduction and physical function in arthritis sufferers. Also there are studies showing improved mental state and feelings of well-being in those with mild to moderate depression and anxiety.

Exercise physiologists funded through Medicare
A new scheme to help people with chronic and complex illnesses has just been announced by Federal Health Minister, Tony Abbott. As from January 2006, people who have conditions such as obesity with co-morbidities such as arthritis,
diabetes and heart disease will be able to access services from exercise physiologists through Medicare’s Enhanced Primary Care Program. They can already receive such a rebate for services provided by physiotherapists, podiatrists, psychologists, speech pathologists and diabetes educators.

Exercise physiologists are health professionals who have graduated from a university course in exercise science (such as that provided at Southern Cross University). To be eligible for Medicare benefits they must be accredited through their association - the Australian Association for Exercise and Sports Science.

What this means is that GPs will be able to access these services for their patients by first coordinating a team care arrangement with at least two approved allied health providers. Patients are entitled to five visits a year to either an exercise physiologist or to one of the other allied health providers mentioned above. These services will attract a rebate through Medicare of $44.95. There may be a gap fee in addition but the rebate will go a long way to funding the service.

This will be a great help for people with a complex problem such as obesity and type 2 diabetes, allowing them to get some help through Medicare for appropriate allied health services. Exercise physiologists are the new addition to the list and they could be vital in helping people become less sedentary in a safe and realistic way.

This scheme is a giant step forward and the NRDGP was part of the lobbying process to bring this change in.

SCU pioneers a management system for M&M&M patients
Over the last three years Associate Professor Allan Davie from the School of Exercise Science and Sports Medicine, Southern Cross University, has pioneered a practical and safe approach to intervene with obese patients with metabolic, mechanical and motivational problems. Most of the patients have started off being sedentary and after fitness testing are given a gentle exercise program that is carefully graded according to ability and need.

Basic measurements have been done including BMI, waist measurements, fasting lipids and BSL, LFTs and HbA1C where appropriate. Quality of life has also been measured using the SF36 scale and long term follow up is planned and results are being published and will be published in later editions of GPSpeak. The ultimate aim is to refine the methods for wider use in the community, particularly now there is about to be support for funding to some degree exercise physiologists.

(1) Hagan et al. The effects of aerobic conditioning and/or calorie restriction in overweight men and women. Med Sci Sports Exer 1986;18: 87-94
(2) Ross et al. Reduction in obesity and related comorbid conditions after diet-induced weight loss or exercise-induced weight loss in men. Ann Intern Med 2000; 133:92-103
(3) R Wing et al. Long term weight loss maintenance. Am J Clin Nutr 2005; 82:222-225
(4) Wei M et al. Relationship between low cardio-respiratory fitness and mortality on normal weight, overweight and obese men. JAMA 1999; 282:1547-53

Andrew Binns is the medical editor of GPSpeak and has a special interest in obesity issues. abinns@gmc.net.au