Let’s talk about weight- why are we so fat?

This post is part of the series weight

Other posts in this series:

  1. Let’s talk about the value of ideal weight
  2. Let’s talk about weight- why are we so fat? (Current)
  3. Diets do not work


Worldwide there is an obesity problem; they call it the “globesity epidemic”. In South Africa 70% of women are overweight and 40% obese (BMI over 30). A third of South African men are overweight.

Despite what the “Fat and Proud”  counter-revolution and our defence mechanisms tell us, it’s not okay to be fat. Obesity results in numerous health problems. In the States, it’s the number 1 cause of preventable deaths. For generations, each generation has died older than the last. This trend is now being reversed because of obesity-related illnesses including diabetes, heart disease, metabolic syndrome, certain cancers and stroke.

When we think about why this is happening, a lot has been said about governments misinforming us. Governments have told us that grains and starches should be at the base of the food pyramid as the most important and biggest source of calories. This error has been cited as a major reason for the rising obesity epidemic. Whilst it has been a useful exercise to challenge old dogma, I do not think that the recommendations as to what we should eat as being the main problem. In my practice, patients may well be confused as to do Banting Diet or Low Fat Diet, but what they should be eating seems the lesser of two evils in what’s keeping them fat. We are eating a lot of chips, sodas and sweets, which we know are bad for us and will make us fat. Yet we still do it. Why?

We are eating a lot of food which we know are bad for us. Why?

Evolutionary theory takes us back tens of thousands years and describes a time when we were very physically active in pursuit of our food; hunting or gathering or a bit later, farming. It did us well to overconsume when food was plentiful (the “elasticity of human appetite” theory) and then storing it as fat for when food was scarce (the “thrifty gene” hypothesis).

Our taste centres sought out and craved sweet flavours which showed us when fruit was ripe; salt, because it is a compound essential to life and fat because it’s a dense source of dietary energy.

With our bodies geared in this way we survived and thrived.

Fast forward to the last few hundred years.

Now food is bountiful and freely available. Added to this, something more malignant is happening. David Kessler, a former commissioner of the FDA, wrote of it in his book “The end to overeating”. Food is being reengineered to form “eatertainment” – food which we crave, seek out and can’t stop eating. Food sky high in salt, sugar and fat ratios. Think of a bag of Nacho Cheese Doritos. Can you stop eating it once you start?

For some people, these high ratios of salt, sugar and fat can actually trigger addiction pathways and they become addicted to (certain) foods. One of my patients described how she once stole from her company’s petty cash to buy fried chicken; a craving triggered by the aroma emanating from a fast food outlet. Unethical food companies are also deliberately overstating the healthiness of their foods. Sugary cereals are a perfect example of this.

Portion sizes have increased, especially of unhealthy, processed food. The cardboard box of popcorn we got at the movies as kids was much smaller than the bucket we get today. Our “elastic appetites” will mindlessly eat the entire portion in front of us.

Obesity is fastest growing in the just above the breadline population group. Junk food is cheap, convenient and comes in huge portions. It is also low in nutritional value, so now we are seeing the tragic situation of malnourished obese families.

Becoming aware of these forces pitted against us is a good start. If we buy processed treats, we will eat them. We will eat them all, especially if we are hungry, then feel terrible for “bingeing”. It might be more prudent to keep that shopping trolley healthy. Which means not shopping when we are starving and more vulnerable to our basic drives being manipulated.

Sun Tzu said, “If you know the enemy and know yourself you need not fear the results of a hundred battles”. Perhaps this is never more relevant than in our war against the bulge.


  • New Scientist May 2017- Call obesity a disease and food a pathological agent? No thanks! Lara Williams
  • Book: Fat chance, the hidden truth about sugar, obesity and disease. Robert Lustig
  • National Geographic Aug 2004- Why are we so fat? Cathy Newman
  • Book: Why we get fat. Gary Taubes

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