Q: Is it advisable to get prescription weight control medications from doctors to lose weight?
A: Doctors in general don’t casually prescribe weight control medications. Doctors will first get a full picture of a patient’s health, to see if pre-existing medical conditions lead to obesity – for example, hypothyroidism, excessive production of adrenocorticotropic hormone or Polycystic Ovarian Syndrome can lead to weight gain, and certain psychotic conditions and psychotropic drugs could also cause weight gain. If obesity is not linked to medical conditions, doctors will advise patients to first try maintain a balanced diet and exercise regime for weight control.
Q: How do we define obesity?
A: There are different standards and indicators for obesity internationally. The most common indicator is Body Mass Index (BMI). For Asians, a BMI higher than 23 is considered overweight, whereas BMI above 25 is considered obese. Men with a waistline exceeding 90 cm, or women with waistline exceeding 80 cm, are also considered obese.
Q: What are the recommended dietary rules for weight control?
A: There are many dietary tips around the world. The simplest one is calorie counting. Simply put, when the energy intake from food is higher than the energy expended, the residual energy will be stored as fat in the body. By the same token, if the energy output is greater than the energy intake, then body fat will be burnt to supply what the body needs.
Q: Is strict dieting an effective means for losing weight?
A: Eating less will of course reduce weight gain, but when dieting is discontinued, body weight could easily rebound, and the body is more prone to weight gain from then on. That’s because dieting reduces not only body fat but also muscle mass. Even when the body is still, energy is spent at Resting Metabolic Rate (RMR). The greater the muscle mass, the higher the RMR. When muscle mass is lessened, RMR slows down and the body burns less energy, so it’s much easier to gain weight. So it’s necessary to take resistance training to maintain body mass when trying to lose weight.
Q: Are aerobic exercises such as jogging the best form of exercise for losing weight?
A: The best weight loss exercise is a combination of aerobic and resistance training. Aerobic exercises can burn fat and enhance cardiovascular functions while resistance training can maintain muscle mass and raise RMR. Resistance training is safer than aerobic exercise, as data show the number of incidences of death or injuries resulting from resistance training is lower than that of aerobic exercises. Some aerobic exercises such as jogging could lead to joint straining, and there are greater risks of dehydration and fall too.
Q: High intensity interval training (HIIT) is all the rage now. Is it effective for weight loss?
A: HIIT is a form of interval resistance training, with aerobic exercise elements included. The advantage of HIIT is that it can be done in shorter duration and has higher intensity. It’s not only effective for losing weight, but also helps to enhance cardiovascular strength. Compared to pure aerobic exercise, HIIT is more effective for losing weight.
Information provided by Dr Samuel Chan Hoi Chung