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A Heavy Concern

May 1, 2022   Return

Overly thin individuals may be the envy of those who struggle to shed extra pounds. While being underweight seems more desirable than being overweight, being underweight has its risks.

Hefty consequences

Those overly thin individuals are at risk of infection (due to easily compromised and weak immune system), hair loss, low muscle mass and unstable hormonal regulation. In addition, underweight individuals are also prone to osteoporosis and anaemia due to the disrupt intake or absorption of important nutrients. Furthermore, underweight women are at risk of amenorrhea (the absence of menstruation) and probable pregnancy complications.

Despite the obesity epidemic escalating at an alarming rate, there is a proportion of the population that is underweight. According to the World Health Organization, the prevalence of underweight (body mass index <18.5 kg/m2) among Malaysian adults was 8.3%.

Lifting the curtain

There is a plethora of causes why individuals may become underweight. Hence, there are as many treatment plans as there are causes. No one size fits all. There is no magic bullet. A treatment plan should be tailored according to each individual. Being underweight, whether body weight is lost purposefully or not, can result from both psychological and physiological factors.

Physical causes of underweight include genetics and illness. Individuals with “lean genes” may have a higher basal metabolic rate, but should be cautious of extreme body weight loss. Body weight loss of more than 2% of total body weight in one week; 5% in one month; 7.5% in three months; and 10% in six months will put an individual at a high risk of becoming underweight.

That aside, some attacks of flu may lead to unintentional weight loss; and some medications may suppress appetite or cause weight loss. Patients should consult their pharmacist if they have recently began a new medication and are now experiencing otherwise unintentional weight loss. Apart from that, some medical conditions do foster underweight, such as hyperthyroidism, diabetes, tuberculosis, HIV/AIDS and cancer.

Many people who are under a lot of stress may experience weight loss due to nausea or a lack of appetite. In addition, individuals suffering from depression frequently experience reduced appetite and unintentional weight loss. For these cases, consultation from a counsellor or psychologist should be sought as well as intervention from a dietitian.

Tackling the issue

The analogous between underweight and overweight continues in treatment plans. Successful weight gain, like successful weight loss, originates from the pairing of a structured diet plan with regular physical activity. The key to gaining weight is to take in more calories than you use.

First of all, there is a need to determine a healthy weight target (body mass index between 18.5 kg/m2 and 24.9 kg/m2) and proceed from that starting point by increasing calorie intake. An extra 500 to 1,000 calories per day is recommended, for a weight gain of 0.5 to 1 kg per week. Similar to weight loss, realistic goals are crucial for proper weight gain. In addition, most of us may find it surprising that weight gain depends equally on physical activity, in order to build and maintain lean tissue. Furthermore, a side benefit of a physically active lifestyle is an increased appetite, which may initiate a positive cyclical effect.

Tipping the scales in a positive direction originates from selecting foods that are calorie-dense but at the same time, still beneficial. Although fast food and unrestricted desserts appear like a miraculous quick fix, nutritious food with protein, vitamins and minerals should be emphasized; instead of mere calories from processed sugars and saturated fats.

Integrating extra calories into a routine diet is often beneficial. For instance, replacing water with milk in oatmeal may add approximately hundreds of calories more conveniently than changing to foods that you may not usually consume. In addition, milk will also add calcium and protein on top of the extra calories.

Smart snacking between main meals also plays a crucial role in weight gain, such as nuts or yogurt can add calories, vitamins and minerals. Furthermore, the weight gain plan may be coupled with polymeric formulae/ nourishing fluids.

Being able to consume anything without noticeable consequences is a fallacy— even underweight individuals have to be aware of fat and sugar intake. Poor dietary choices may lead to illnesses such as heart disease or stroke, irrespective of body weight. Consult your dietitian if you need professional help in dealing with the difficulties of gaining weight!


Institute for Public Health. (2011). The fourth national health and morbidity survey (NHMS IV). Kuala Lumpur: Ministry of Health Malaysia.

World Health Organization. (1998). Preventing and managing the global epidemic. Report on a WHO Consultation on Obesity. Geneva: World Health Organization.

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