As adults, every one of us may, at some point of our lives, be faced with the issue of having put on weight or too much weight perhaps. How do we know if we are in the healthy weight range and if we are not, how much has this excess weight impacted our lives or health?
Obesity is defined as a chronic medical condition in which excess or abnormally distributed body fat can negatively impact one’s health. Studies of different populations around the world have shown that a higher amount of total body fat and/or of fat deposited in the abdominal area is associated with increased risks of developing a range of health problems and reduction in lifespan. As a chronic condition, obesity tends to run a progressive course with weight regain often occurring after weight loss efforts are stopped.
The following 2 measurements are used to assess for overweight or obesity: (1) Body-mass index (BMI), a measure of the amount of body fat based on one’s weight and height, and (2) Waist circumference, which gives an indication of the body fat distribution in the abdominal area (visceral fat).
The BMI is calculated by dividing a person’s weight in kilograms by the square of his or her height in metres. Since Asians tend to have higher body fat especially of visceral fat than Caucasians with the same measures, this means that Asians have a higher risk of developing obesity-related diseases at a lower BMI and waist circumference compared to Caucasians. Therefore, the normal cut-offs for BMI and waist circumference for Asians are lower than that for Caucasians to reflect these health risks.
The WHO-recommended BMI ranges are divided into four categories:
The Singapore National Population Health Survey (NPHS) 2020 showed that 28.8% and 10.5% of adult Singapore residents have overweight and obesity respectively. Based on the recommended Asian BMI cut-offs, the prevalence increases to 38% and 21% for the overweight and obesity health-risk-BMIs respectively, reflecting that nearly 3 in 5 adults in Singapore are in the unhealthy BMI range. There has also been an increasing trend since 2017.
There are more than 200 medical conditions associated with obesity, some of which are highlighted below:
People who have developed obesity-related medical conditions (listed above) tend to have more severe stages of obesity especially when these conditions are severe. Weight loss can reduce the severity of these obesity-related conditions or even lead to their remission (resolution).
When food intake (total calories consumed) is greater than the calories one burns up (energy expenditure) over a sustained period of time, weight gain with increase in body fat will take place.
However, there are multiple factors which can lead to the increased food intake and/or the reduced energy expenditure. A genetic tendency, a maternal history of obesity and type 2 diabetes during pregnancy, consumption of certain medications, certain hormonal disorders like low thyroid levels, stress, disruption to sleeping habits like shift work and insufficient sleep, social influences are some of the factors which can increase one’s tendency for weight gain. Addressing these triggers and factors is essential in the management of overweight and obesity.
Before one embarks on weight loss, certain fundamental issues need to be considered.
Assessing Severity of Obesity1) The severity of obesity reflects the impact of obesity on one’s health, quality of life and life expectancy. 2) More urgent attention to weight loss is needed in those whose health and quality of life have been more negatively affected by obesity, mainly to treat the concurrent obesity-related conditions and improve the quality of life. The severity of obesity determines the type of weight loss treatment you doctor will recommend.
Goals of Obesity
It is important to determine what the goals of weight loss are. The focus should be on improving one’s health by reducing the ill-effects of obesity.
Improving one’s quality of life or mental distress related to having obesity can also be a tangible goal.
A weight loss of 5-10% can significantly improve obesity-related medical conditions e.g. improvement in blood pressure and blood sugars, reducing the severity of obstructive sleep apnea (OSA). In some cases, if hypertension, diabetes and OSA is mild, weight loss of 10% can even reverse these conditions while the weight loss is maintained. Hence, a weight loss of 5-10% can be a good initial goal over the first 3-12 months.
1) Lifestyle modification
This is fundamental for weight loss efforts to be effective and successful. The best weight loss method is one which is safe and can be adhered to. The change in lifestyle brought about by that method can hopefully be as sustainable as possible to prevent weight regain in the long-term.
i) Identifying factors which have led to the weight gain is a vital start. Some of the often under-recognized triggers of weight gain include stress, poor sleep hygiene, change in living environment or lifestyle routines, acute medical illnesses or new medications. These must be rectified and addressed concurrently while implementing other weight loss modalities.
ii) Dietary intervention:
A change in dietary habits is necessary for weight loss to occur. In general, a reduction in 500kcal a day can lead to a 0.5kg weight loss a week. There is no “best diet” and each dietary intervention should tailor to one’s lifestyle.
Most importantly, the change in dietary habits should focus on getting oneself healthier in addition to weight loss. These dietary changes must not worsen existing medical conditions nor cause more complications. The more sustainable the change in eating habits is, the more successful one is able to lose and keep the weight off.
A dietary intake high in fibre, unsaturated plant-based fats, with adequate lean protein and low in salt, saturated fats and refined carbohydrates is generally recommended and beneficial for those with obesity-related metabolic conditions and in reducing risk for heart disease.
iii) Increase in physical activity and reduction in sedentary time: Increasing physical activity and reducing inactive time is necessary in weight loss treatment. Being physically active has many other health benefits beyond weight loss. In general, to optimize health and fitness, and to prevent disease, it is recommended for adults to participate in at least 150 minutes per week of moderate intensity aerobic exercise (e.g. 30 minutes on at least 5 days per week). This can also be achieved by accumulating intermittent bouts of at least 10-minute duration each time.
To promote weight loss and for long-term weight maintenance, higher levels of physical activity with dietary change is recommended, with 250-300 minutes a week of moderate intensity or 150 minutes a week of vigorous intensity aerobic exercise. Strength training (resistance exercise) can also be added to aerobic exercise to increase muscle strength and physical function.
For people who are physically inactive, it is strongly recommended to start at a low intensity as tolerated and progress to the recommended levels. People with joint pains, previous injuries, medical conditions such as heart disease, diabetes mellitus, or experience chest pain or breathlessness on minimal exertion, should consult your doctor first before embarking on an exercise programme.
iv) Behavioural therapy:
Psychological factors play an important role as a cause of obesity. Stress, emotional eating and mood disorders (depression / anxiety) can lead to weight gain and can sabotage weight loss efforts if left unaddressed. Cognitive behavioural therapy and intervention by a psychologist or a psychiatrist will be beneficial in these cases.
2) Weight loss medications (Anti-obesity medications)
For many people with obesity, treatment with anti-obesity medications will need to be added to lifestyle changes to achieve the weight loss needed to attain health benefits. In others, weight regain occurs after initial successful weight loss and anti-obesity medications are needed at this stage.
There are 3 types of weight loss medications approved for use in Singapore. Each medication has its own indications, weight loss effect and side effects and may not be suitable for use in everyone. It is best to discuss with your doctor on the appropriate use of these medications and the monitoring required when you are on the medication.
3) Bariatric procedures and surgery For those with more severe stages of obesity, a very high BMI in the absence of an obesity-related condition or those with frequent weight yo-yo, bariatric procedures and surgery may be recommended in addition to the above measures mentioned.
Bariatric procedures include the intragastric balloon which can be performed by a patient swallowing a capsule under X-ray guidance and a doctor’s supervision; and the endoscopic sleeve gastroplasty performed via endoscopy.
The types of bariatric surgery commonly performed in Singapore are sleeve gastrectomy and Roux-en-Y gastric bypass which are mostly done via the key-hole method (laparoscopy).
An experienced multi-disciplinary healthcare team needs to be involved in the care of those undergoing bariatric procedures or surgery. After the procedure or surgery, regular follow-up with the team is necessary to ensure that there are no complications related to the procedure or surgery and that in the long term, the maximal effect of weight loss can be achieved.
4) Weight loss supplements There is little scientific evidence that weight loss supplements are effective for weight loss. In fact, many over-the-counter supplements touted to be very effective contain medicines which are withdrawn from the market or may contain high doses of laxatives and diuretics. These have led to dangerous side effects after consumption.