How did we become overweight?

To understand how to lose weight, its necessary to understand how we become overweight in the first place. There are many reasons, but scientists have discovered a few key points. The obesity epidemic has occurred not because of diseases or genetics (which haven’t changed), but because of our lifestyle choices (which have). Having said that however, if you gained weight rapidly within a few weeks or months it is important to make sure you don’t have a medical cause. You can read more about such causes in Step 1. Another fact that scientists have uncovered is that once you lose weight, it is often difficult to maintain a lower weight for more than a year. I will be explaining how to make sure you keep the weight off permanently in Step 5.

How did we become overweight?

To answer this question, we need to go back millions of years to the time of our human ancestors. In those days, food was scarce and you had to burn a lot of calories to get it. We became farmers about 12000 years ago. But for more than 3 million years before this, we were hunter-gatherers. We depended on scavenging for what bits and pieces of food we could get from nature. Starvation was frequent, and a common cause of death.

Metabolism in the prehistoric eraAdapting to starvation

Our endocrine system and our metabolism learnt to adapt to food scarcity. You can see the effects of this even today. For example, we actually have more than 5 hormones (adrenaline, noradrenaline, glucagon, growth hormone, cortisol and others) to raise blood glucose levels when food is in short supply. On the other hand, having too much food was so rare that we only have one major hormone (insulin) to lower glucose!

Food scarcity also meant that human metabolism became optimized for a low-calorie environment. Energy metabolism became so efficient that you could be very physically active without burning many calories. Does that sound familiar? It’s the reason why you have to exercise so much for so long to burn fat and lose weight!

Fat tissue and the endocrine system

The main adaptation to starvation was fat metabolism. Think of fat tissue as the endocrine system’s fridge; a site for energy storage to keep us alive during periods of starvation. When you eat food, our digestive system breaks it down and we start to absorb glucose. Our pancreas makes the hormone insulin to lower glucose levels. But this hormone also has the effect of converting glucose into fat tissue. This helps our body store surplus energy. Carbohydrates raise blood glucose levels higher than any other food. Over time, eating more carbohydrates than necessary can lead to increased fat tissue and weight gain. To make matters worse, we don’t have any endocrine mechanisms to help us lose weight once it has been gained.

In the prehistoric era, fat tissue actually protected us. In modern days however, staying overweight for years and decades disrupts our endocrine balance. It is associated with a number of diseases, including heart attacks, gallstones, arthritis, high blood pressure and raised cholesterol [R1]. Being overweight or obese can also shorten your life [R1].  A large number of cancers are linked to obesity. They include breast cancer, colon cancer, kidney cancer, uterine cancer and many others [R1]. Click here if you’d like to find out more about the diseases linked with being overweight.

Modern life and weight gain

Foods leading to obesity and being overweightToday we live in the era of cheap and abundant food. Endocrinologists like to call this an “obesogenic environment”.  Calorie-dense food surrounds us in abundant quantities. Food manufacturers have loaded processed food with fats, sugars and salt which entices us to eat even more (see Step 3 to learn more about this). Physical activity has been engineered out of our lives. Today you can live your whole life without much physical activity, as everything is becoming mechanized.

Weight gain from our lifestyle is usually gradual, typically over a year or more. Let’s say you like Coca-cola and drink one can more than your calorie requirement each day. That is an extra 140 calories. You can also get the same number of calories from around 15 Pringles chips or one bagel. One estimation is that this can lead to around 12 grams of extra fat per day [R1]. You will need to jog for about 15 minutes each day to burn that amount of extra calories. So even having an extra hundred calories each day adds up to weight gain over months and years.

Is all weight gain due to poor food choices and a lack of exercise? Clearly it isn’t (see Step 1). But it definitely is playing a large role in most of the people. Just as obesity has many causes in different people, the best treatment for it also varies in different people. However,  research does identify a few key steps that can help almost all people lose weight. This is what I’ll be describing further in the steps to weight loss. Click on the button below to start!

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