Taking a practical, comprehensive lifestyle approach will help reduce the risks of complications. By Michael Lim

IN most affluent societies, an increasing proportion of the population tends to be overweight or obese and hence it is not surprising that weight loss has become a common desire for many, both for aesthetic and medical reasons. Before jumping onto the weight loss bandwagon, understanding the latest American Heart Association guidelines published in November 2013 in the Circulation Journal provides one with a practical approach to the management of excessive weight gain.

Who needs to lose weight?

Many people who undergo weight-loss programmes do it primarily for aesthetic reasons rather than for medical reasons. From the medical view point, it is good to understand which individuals can benefit from weight loss. Most criteria for the definition of overweight or obese condition utilise the Body Mass Index (BMI) calculation. BMI can be calculated as weight in kilogrammes divided by the square of the height in metres. Current US definitions consider a BMI (kg/m2) of 18.5 to less than 25 as normal weight, 25 to less than 30 as overweight, 30 to less than 35 as class 1 obese, 35 to less than 40 as class 2 obese and 40 and above as class 3 obese or extreme obesity. These definitions categorise individuals into different risk categories for heart disease and obesity related conditions.

One of the important factors to consider before deciding whether the individual will benefit from weight-loss programmes is to determine whether there are pre-existing medical conditions. The overweight or obese individual has to be assessed for evidence of heart disease, diabetes, high cholesterol and high blood pressure. For those whose BMI is 25 to less than 35, a waist circumference measurement of more than 88cm (or 35 inches) for women and more than 102cm (or 40 inches) for men indicates an increased risk of heart and metabolic disease. Obese individuals are also more likely to have sleep-related problems as a result of obstruction to their air passages in the nose and throat region.

The latest recommendations state that those who will benefit from weight loss are those who are in the obese category with a BMI of greater than 30. However, overweight individuals (BMI 25 to less than 30) who have at least one risk factor for heart disease, such as high blood pressure, high cholesterol, diabetes, elevated waist circumference or obesity-related medical problems will also benefit from weight reduction.

Weight management goals

The most important starting point for any successful weight management programme is to set realistic goals for weight loss. While it is understood that the greater the weight loss, the greater is the potential benefit, a realistic initial goal will be to set a target weight loss of 5-10 per cent within the first six months.

Sustainable weight loss regimes require a net energy loss by burning up calories in the body and reducing the calorie intake. It is recommended that a net energy loss of at least 500 kilocalories (kcal) be achieved daily. Depending on the physical activity of the individual, this can usually be achieved with a daily calorie intake of 1,200-1,500 kcal/day for women and 1,500-1,800 kcal/day for men.

Generally, very low-calorie diets (below 800 kcal/day) are only to be commenced under medical supervision. In some individuals with pre-existing medical conditions such as Gilbert’s disease, the individual can become jaundiced within a few days of commencing on a very low calorie diet. As Gilbert’s disease, a benign hereditary condition, has an estimated prevalence of 5-10 per cent of the population, proper assessment must be performed before commencing on such diets.

Comprehensive lifestyle approach

A comprehensive lifestyle approach is key to successful weight loss programmes. Effective weight management programmes require that lifestyle adjustments be made during regular face-to-face visits of at least fortnightly frequency. Such programmes must include a reduced calorie diet with a planned daily energy deficit of 500 kcal or more, commencement of a regular physical exercise regime beyond the individual’s usual activity level, and motivational drivers for adherence to a reduced calorie and increased physical exercise regime. Generally, a weight reduction of 5-10 per cent is achievable at the end of six months with adherence to such a programme. The weight loss will plateau and weight will stabilise after six months. Further weight loss will require adjustments to the calorie intake and physical exercise to maintain further net energy deficits.

For those who are unable to achieve or maintain a weight loss despite undergoing a comprehensive lifestyle programme, other adjunctive measures may be considered such as drug treatment with medication such as Xenical (orlistat).

Weight reduction procedures

There are some who are unable to achieve a sustainable weight loss despite undergoing comprehensive lifestyle adjustment programmes. Those in this category who have extreme obesity (BMI of 40 or more) or BMI of 35 or more in the presence of at least one risk factor for heart disease, weight reduction surgery (bariatric surgery) can be considered if there are no contraindications.

Bariatric surgery reduces weight by reducing the size of the stomach or by reducing the capacity to absorb food or by a combination of both. The combined approach surgery, also called the Roux-en-Y gastric bypass, is considered as the “gold standard” weight reduction surgical procedure. The advantages of these surgeries are rapid weight reduction, significant decrease in death from heart disease, diabetes mellitus, and cancer. The net effect is a 40 per cent decrease in death. An analysis of several databases by Buchwald, published in the Journal of the American Medical Association in 2004, stated that almost two in three had reduction in blood pressure, almost three in four had reduction in cholesterol and diabetes improved or resolved in five out of six. The Swedish Obese Subjects study, published in the New England Journal of Medicine in 2004, showed that after bariatric surgery, there was a 72 per cent reduction in risk of heart disease at five years, with sustained benefits at 10 years and 59 per cent reduction in death from heart artery disease at 15 years. Bariatric surgery has also been shown to benefit obese individuals with impaired heart function resulting from obesity. As a result of the significant beneficial effects of bariatric surgery on diabetes, being an obese type 2 diabetes mellitus with BMI of 30 or more is now considered as one of the indications for bariatric surgery.

Sustainable weight loss

There is never an easy way to lose weight without restricting calorie intake and increasing physical activities. While becoming increasingly popular for removing fat, liposuction is not a recommended method of weight loss and it carries no evidence of sustainable health benefits and yet carries a real risk of serious complications, including death.

Ultimately, weight loss is a matter of will. I am reminded of an obese patient of mine who has been seeing me for 20 years. During his regular visit earlier in the year, he came for his regular review in my clinic and expressed delight with his significant weight reduction of more than 10 kilogrammes within six months. After 20 years of obesity, he suddenly took a decision to walk 45 minutes on his treadmill machine every morning and night, and made a conscious effort to restrict his calorie intake. The result was a healthier person with normal BMI, achieved purely by willpower. Remember that there is no easy way out, and spending thousands of dollars at a slimming centre or on slimming foods can rarely produce sustainable weight reduction without willpower.