Sugar is widely accepted as the culprit behind soaring obesity rates. But exactly how is the white stuff making us fat?
For decades eating fat, specifically saturated fat found in meat and dairy, was blamed as the leading cause of many conditions and diseases ranging from obesity to cancer to heart disease. With the research behind those findings now widely discredited, attention has turned to finding the real culprit fuelling rocketing obesity rates in the Western world: sugar.
Today 67.1% of men are classified as either overweight or obese, according to the latest Health Survey for England report, which is a fourfold increase since the 1970s. That’s the same decade in which the shaky evidence that eating fat made you fat emerged, and in which the masses were told to avoid it in favour of increasing their consumption of carbohydrates – including sugar, which was added by the bucketload to low-fat foods to make them palatable.
The typical British adult now consumes 12.1% of their daily calorie intake from sugar, with 26% of that figure coming from sweets and chocolate, 25% from cereals, cakes and biscuits, 21% from soft drinks and 10% from alcohol, according to figures from the National Diet and Nutrition Survey. We ditched fat, a macronutrient we have eaten since climbing down from the trees, for sugar – a far more recent dietary addition – and what happened? We all piled on the pounds. This is especially true in the UK, which in 2014 was the third fattest country in Europe, behind only Iceland and Malta, according to the Global Burden of Disease study published in medical journal The Lancet.
The war on obesity was being lost – mainly because it was being fought against the wrong enemy. But now, after years of misunderstanding, misinformation and misguidance, it’s sugar that’s firmly in the crosshairs.
In 2015, a British Medical Association report said that every year the effects of poor diet cost the NHS £6 billion and claim 70,000 lives, and called for the introduction of a tax of 20% on all sugary drinks, including fruit juices. Professor Sheila Hollins, who led the team behind the report, said that the introduction of the tax could reduce the prevalence of obesity in the UK by around 180,000 people. The following year the government announced it was planning to adopt the tax, and in his March 2017 budget chancellor Philip Hammond confirmed it would be implemented from April 2018.
A separate 2015 report from the Scientific Advisory Committee on Nutrition (SACN), a body comprised of highly-regarded academics, suggested after a sevenyear enquiry into potential solutions to the obesity crisis that significant changes be made to the nutrition advice given to the public. The central proposal was halving the maximum daily limit of sugar from 70g to 35g, which is the equivalent to one can of fizzy pop. The suggestions were submitted to Public Health England, which advises the Department of Health (DH) on policy. However, in a move condemned by many health campaigning groups, the DH shelved the report and set no timeframe for its publication.
Despite this setback, the government’s adoption of the sugary drink tax and the lack of public resistance to it shows a growing recognition of the severe impact sugar has on our health.
But how exactly has sugar made us fat?
BREAK IT DOWN
There are three types of sugars found naturally in whole foods and they are beneficial to your diet because of the vitamins, minerals and other nutrients they also contain. These are polysaccharides, such as starch and amylose, which are found in grains; monosaccharides, such as glucose, fructose and galactose, which are found in fruit; and disaccharides, such as sucrose, lactose and maltose, which are found in milk.
When you eat these foods, the sugars are broken down into glucose in the gastrointestinal tract. The glucose is then transported via the blood to the organs and other tissues, including the brain, for use as energy. If this energy is not needed, it is stored as glycogen in the liver and muscles. If your glycogen stores are already full then glucose is converted and stored in fat cells.
Since so many healthy foods are natural sources of sugar, why is it making us obese? The answer is simple. It’s the sheer amount of the stuff we’re eating. And, perhaps more significantly, the amount we’re drinking.
“We ditched fat for sugat and what was the resullt? We piled on the pounds”
Because sugar is used as an additive to increase sweetness and palatability in so many products – especially fast food, confectionery and convenience meals – it’s all too easy to consume huge amounts of added sugar without even realising it. When you factor in a daily large cappuccino (13.8g of sugar) and glass of orange juice (25g), a lunchtime fizzy drink (37g) and a pint of cider after work (20.5g), it’s not hard to see how it’s possible to consume far more than your daily recommended intake of sugar from drinks alone.
Most added sugars are in the form of sucrose. When it’s broken down during digestion, the result is a molecule of glucose and a molecule of fructose. If your liver’s storage capacity is full, the fructose is converted and stored as fat. Added sugars provide nothing but energy in the form of carbs, with no other nutrients – and fructose is even more damaging because it fails to activate satiety centres of the brain and leaves people feeling hungrier, according to research published in the Journal Of The American Medical Association.
Over time this can result in an increased calorie intake, because the calories from sucrose no longer satisfy you, so you eat more of it. The result is a vicious cycle of overconsumption and a lot of excess calories being stored as body fat. Unsurprisingly, there is a strong statistical association between people who consume the highest amounts of added sugar and rates of obesity, for all age groups, according to the American Journal Of Clinical Nutrition.
LONG TERM DAMAGE
One of the most damaging effects of excessive sugar consumption on health is the development of insulin resistance. Insulin is a hormone which facilitates glucose’s entry into muscle and fat cells from the bloodstream (imagine each cell has a locked door and glucose can’t get in until insulin arrives with the key).
The condition of insulin resistance occurs when the body produces insulin but can’t use it effectively, so glucose remains in the bloodstream instead of being absorbed by the cells. Over time the insulinproducing cells of the pancreas cease to function, so blood glucose levels stay above normal ranges. This results in type 2 diabetes, and also damages nerves and blood vessels, leading to serious health issues such as heart disease and kidney failure.
The simple truth is that if you want to get a lean and healthy body then you need to keep a closer eye on your daily sugar intake. Sticking to natural sources with their added fibre and other nutrients will keep you on the right track – so long as you make fizzy drinks, convenience foods and take-aways an occasional treat and not a daily occurrence.