WE should all know that obesity is a condition where a person has accumulated so much body fat that it might have a negative effect on their health.

If a person’s body weight is 20 per cent or higher than what it should be, given their height, then that person is considered to be obese. Medical personnel use a calculation called body mass index (BMI), which has a cut-off point of 25, above which the person is considered overweight, and when above 29, the person is undeniably obese.

The fact that no country has experienced a decrease in obesity among its population over the past 40 years as well as other patho-physiological factors associated with obesity have led some researchers to believe that obesity is a chronic disease and not a lifestyle choice. In a global study published in the journal The Lancet, researchers tracked the trends in body metabolic indices (BMI) from 1980 to 2013, and the proportion of adults with a BMI of above 25 increased relentlessly with the passage of time in both upper-as well as lower- and middle-income countries.

A chronic disease

So, while individuals may disagree over what is the primary cause of obesity, the final pathway is pathophysiological, similar to diabetes and other chronic diseases, and not merely a voluntary control over energy balance. Consequently, just like diabetes, obesity is never ‘cured’, although a person’s BMI may be under very good control.

Once people become obese, they will still have the disease of ‘obesity’ even though they have lost weight and no longer meet the definition of obesity by external measurements.

We see the pattern beginning for some in early childhood when some mothers for various reasons stopped breastfeeding early and introduced the ‘bottle’ to their child. Overfeeding at this stage caused excess fat cells to be formed in the infant, and once formed, these cells never go away. Depending on the eating and exercise pattern of the child as he or she grows into adulthood, they may be perpetually plump or even obese.

On the contrary, children who were solely breastfed for the first year of life rarely ever become obese as adults. Due to the breastfeeding, few fat cells were laid down in their system as infants. Hence there are many reasons for the slogan: ‘Breast is best’!

Obesity in adults

When we tell obese individuals to ‘eat less and exercise more’, this shows little understanding of the biological basis of obesity and its many causes.

The human body will defend its fat mass and so, if a patient undergoes liposuction to remove fat, all factors being equal, that fat will grow back to where it was before removal and it will grow back lumpier and bumpier than it was before.

If there is a pathophysiology that maintains extra body fat beyond what is normal or healthy, then that same pathophysiology will drive us to overeat in the case of obesity. Doctors who treat obesity begin by taking a history to identify triggers for eating, exercise patterns, stress levels, sleep patterns, related body circadian rhythm and its imbalances, and any medication that can promote obesity. The belief by some researchers is that overeating does not cause obesity; obesity causes overeating.

Conversely, dieting and under-eating does not solve or cure the problem of obesity; effective treatment of obesity as a chronic disease is what produces under-eating. This includes a healthy diet, exercise, stress reduction, improved sleep health and the re-establishment of normal circadian rhythms, anti-obesity medications (such as metformin) that promote weight loss, and bariatric surgery.

Individual treatment

Interventions that do not work over the long term include calorie restriction on a diet that is no different chemically from what the person was eating before, malabsorptive medication such as Xenical, and devices like the intra-gastric balloon that restricts food intake or cause malabsorption. Further, more exercise, if individuals are already exercising regularly, is unlikely to promote significant long-term weight loss.

Each anti-obesity treatment works well only in a small sub-group of people, and there is wide variability in response to the various interventions. This suggests that there are multiple subtypes of obesity.

The power of genetics to help guide the treatment of obesity is also an area for further research to develop more effective obesity prevention strategies.

So, the concept of obesity as a physiologically driven chronic illness that requires treatment based on physiologic-based interventions has become very pervasive, with the belief that treatment must be individualised to maximise the chance of success. An important element for success is to identify small steps that individuals and their families feel are achievable, rather than imposing larger goals that they might not be able to sustain.

The slowing of the acceleration in weight gain is the first target. Everything then follows from there.

Dr Derrick Aarons MD, PhD, is a Jamaican family physician and consultant bioethicist; a specialist in ethical issues in health care, research, and the life sciences; and is the health registrar and head of the health secretariat for the Turks & Caicos Islands.