Why we gain weight and what to do about it

We’ve all heard about the global ‘obesity epidemic’. The statistics are truly alarming. In the USA in 2009-10, more than 2 in 3 adults were overweight or obese, and more than 1 in 3 were obese. In the UK and Ireland in 2015, 62.9% of adults were overweight or obese, and obesity among adults rose from 14.9% to 26.9% between 1993 and 2015. If current trends continue, obesity is predicted to affect 60% of adult men, 50% of adult women and 25% of children by 2050.

For some, weight gain is merely an inconvenience or an embarrassment. For others, it is life-changing. Globally, there are estimated to be 415 million adult diabetics (90% of whom have type 2 which closely associated with obesity). It is expected to affect one person in 10 by 2040 (642 million). It is estimated that 1 in 2 adults with Type 2 diabetes are undiagnosed. In England, there are nearly three million people currently diagnosed with diabetes and over 7,000 a year have amputations caused by their diabetes. In the UK in 2012, it was reported that about £10 billion (nearly 10% of NHS spending) goes on direct treatment of diabetes per year, and another £14 billion for indirect costs. Diabetes was projected to cost £39.8 billion overall by 2035/36.

Despite all the public health recommendations over many decades, there has not been a significant improvement in these statistics. So, why do we put on weight so easily? For many years, we have been bombarded with simplistic messages: eat less, move more; calories in, calories out; fat makes you fat; eat low-carb; sugar is the enemy. However, the truth appears to be more complex.

What can we learn from existing pre-industrial cultures who don’t have these problems? Fortunately, there are still some pre-industrial cultures who have not yet succumbed to a modern diet and lifestyle, and whose way of life closely resembles that lived by humans for millions of years. This is not to say that their way of life is inherently superior to modern life (who would want to give up antibiotics, emergency medical care, electricity, the internet, and so much more?). However, whether we like it or not, human biology has evolved a certain way, and there is a serious mismatch between our genes and much of modern life.

Some experts estimate that it is 2.6 million years since the genus Homo first emerged; we were hunter gatherers for 99.5% of that time, subsistence farmers for 0.5 % and industrialised for less than 0.008%. That is just not enough time for our biology to catch up with industrialised living. So, what is it about modern life that could be causing obesity?

Think about the life of a hunter gatherer. You might have enough to eat today, but you don’t know if you will be eating anything tomorrow. The availability of food depends on being able to find game to hunt and having the skill to kill it, and gathering fruit, vegetables and nuts. None of this is certain. Over millions of years of human evolution this meant that we evolved to eat as much as possible of the most nutritious food available, whenever we could. Anthropologists have observed that modern day hunter gatherers like the Aché of Paraguay and the Hadza of Tanzania may gorge themselves and eat a litre of honey in one sitting. Of course, for them, honey is an occasional treat.

This is just one example of how, as Stephan Guyenet points out in his new book, The Hungry Brain, humans are hard-wired to eat as much as we can whenever we can because for most of our evolution we lived in an environment of food scarcity. Because food calories provide the energy essential for survival and reproduction, it made perfect sense for us to make the most of whatever was available, for who knew how long it would last? Whilst these behaviours made perfect sense for millions of years, and ensured human survival to this day, they are extremely unhelpful in our world of food abundance. In attempting to follow the public health advice to ‘eat less and move more’ we are trying to behave in ways directly opposite to how our brains are wired. No wonder it’s difficult!

What can we do? We cannot change how we are wired, but we can make smart choices, without relentless, and probably unsuccessful, self-denial. An important concept is that of the calorie-density of food. We are not only wired to eat whenever food is available, but also to seek out the most calorie dense food possible. In our world, this means we are attracted to processed foods like ice cream, pastries, crisps, fries, white bread, pizza, cakes, and so on. We know they are not good for us but our brain craves them. However, by substituting foods that are less calorie-dense like fruit, vegetables and meat (in other words, natural unprocessed whole food) we can feel full whilst consuming less calories.

This is one of the reasons why many people have been able to lose weight by eating a low or moderate carbohydrate diet; they naturally eat more whole foods and fewer calorie-dense processed foods full of refined carbohydrates. The point is not the macronutrient ratio (relative quantity of protein, fat or carbohydrates) but the quality of the food, including carbohydrates.

There are a lot of very smart food manufacturers in the world whose survival depends on getting us to buy their processed food. Naturally they engineer their products for maximum palatability (and sales) by using carefully designed combinations of sugar, fat, salt and starch. Although they spend billions of dollars a year on advertising their products, we can eat perfectly well, without going hungry, by eating whole foods instead. It makes good sense to banish the biscuits, sweets and processed food from the house, wherever possible.

What about you? Do you want to lose weight? Have you had success, or have your efforts left you tired, irritable and hungry? Get in touch for a free health coaching discovery call. Or comment below.



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