Is Sugar to Blame?

Is Sugar to Blame?

Is Sugar to Blame?


Karen Coghlan aka The Nut Coach is a nutrition coach, sports nutritionist, writer, personal trainer, PhD, kettlebell nut, and barbell lover. When not coaching clients (or deadlifting or squatting), she can be found drinking coffee and writing her weekly nutrition column for national newspapers in Dublin, Ireland

Sugar has gained a bad reputation for its role in the global obesity crisis and for contributing to the rise in potentially fatal health related problems including Heart Disease, Cancer, Stroke, and Type 2 Diabetes. Many Tv shows and documentaries have helped position added sugar as Public Enemy #1 in the Western diet, directly responsible for causing disease.
But is it? Not in my opinion.

According to the Irish Heart Foundation, obesity is defined as a disease when there is an excess of fat in the body that adversely affects our health. This happens when we eat more calories than we need. The reason we overeat is not as easily explained, but it is driven largely by our environment. More often than not, we go into auto-pilot and eat what is in front of us for no other reason than because it’s there, even in the absence of hunger. The amount of food we eat is strongly influenced by external factors such as portion sizes, the visibility of food through advertising, and access to ready-to-eat highly palatable foods. The result is that we eat more food than we need, leading to weight gain.

No one food, not even sugar, is to blame for our global health crisis. It’s an extreme statement and shifts the focus away from the real cause of the problem.

The hard bottom line is that the overconsumption of highly palatable foods, which are calorie dense and generally tend to be rich in both sugar AND fat, is one of the driving forces behind the obesity epidemic.

Sugar News Flash

Sugar is a blanket term and does not mean just the white table sugar that we sprinkle in our tea. Sugars are a simple form of carbohydrate, which are derived from natural sources including fruits, vegetables, milk and honey, as well as the processed brown, white, and powdered sugars.

Other forms of carbohydrates include the complex kind; namely starches and fibres, found in beans, sprouting vegetables, and whole grains, which are generally not sweet to taste.

Carbohydrates are essential to life. They provide us with energy, to enable our brains to function and our bodies to run efficiently. Regardless of their source, all carbohydrates are broken down into simple sugars before they are absorbed by the body and used for energy in the form of glucose (aka blood sugar).

Same Same or Different?

The most common simple carbohydrates in the diet are fructose, sucrose, and lactose.
Fructose is a sweet simple sugar found naturally in fruit and vegetables and makes up for more than half of the sugar in honey. However, most of the fructose in our diets come from high-fructose corn syrup in sugary fizzy drinks, sweets, jams, and desserts. Much of fructose is converted to glucose by the liver, but if consumed in excess then it can be stored as fat in the body.

Sucrose, made from fructose and glucose, is the most common double sugar in our diets and is found naturally in sugar cane, sugar beets, honey, and maple syrup. It can also be processed to make brown, white, and powdered sugars. Lactose is the only sugar found naturally in dairy products, and is broken down into glucose in the body or stored as energy for future use.

Added or refined sugars are not nutritionally or chemically different to naturally occurring sugars in foods. What distinguishes one type of carbohydrate food from the other is the rate at which it is broken down and absorbed in the body, as well as the other nutrient content of the food. Refined simple sugars, such as fructose and sucrose that have been added to fizzy sugary drinks, sweets, cakes, biscuits, fruit juices, and ice-cream, have been separated from their plant sources, and therefore have lost some of their inherent nutrients. These type of calories are often referred to as “empty calories” as they offer little nutritional value beyond the calories they contain. Whereas naturally occurring sugars found in milk, fruits and vegetables, provide not only energy but also fibre and essential micronutrients. For example, dairy products also provide an array of essential nutrients that contribute to a healthy, balanced diet, and have a protective effect against heart disease, stroke, diabetes and certain cancers. They are also a source of protein, calcium, and vitamin D, all of which are critical to fight osteoporosis.

What do the Guidelines Say?

Governments and health organisations around the world have published dietary guidelines for sugar intake as a means of reducing to risk of obesity, and tooth decay. According to the Food Safety Authority of Ireland’s "Healthy Eating Guidelines", in terms of calorie and nutrient goals, 10% or less of our total intake should come from *sugar. The World Health Organisation’s “Guideline in Sugars Intake for Adult and Children”, advise reducing the intake of free sugars (which excludes fresh fruits, vegetables, and sugars naturally present in milk) to less than 10% of total energy intake.

(*Sugars, in this case, are “non-milk extrinsic sugars” and include table sugar, syrups, fruit juice and sugars added to foods such as cakes, biscuits, confectionery, breakfast cereals, sweets, soft drinks, tinned and stewed fruit, jams, preserves, yoghurts and milk puddings.)

So what does this mean? Let’s put it into context. For example, an average adult female thrives on ~2000 calories per day. If she allocates 10% of these calories to free sugars, that equates to 200 calories. There is approximately 4 calories per 1g of sugar. Therefore, the recommended maximum free/added sugar intake for an average female adult is 50g, which is roughly 12.5 teaspoons of sugar (4g per teaspoon). Common belief is that the World Health Organisation (WHO) recommends we cut our consumption to less than 6 teaspoons (25g) a day for health benefits (to reduce dental caries, not overweight or obesity). However this is actually half of what they currently recommend, as outlined above. Using a percentage of total calorie-intake for sugar intake is more practical than simply allocating 6 teaspoons across the board for everyone, so each individual’s weight, activity levels, and energy requirements can all be accounted for when assessing sugar intake.

What to Look Out For

If you are concerned about the amount of added sugar in your diet, then a good place to start is with the obvious sources of sugar, which account for nearly 80% of added sugars, such as sugary fizzy drinks, snacks and sweets.

Most of the evidence linking added sugars to obesity and other chronic diseases is done measuring sugary drinks rather than all forms of added sugars, so encouraging better alternatives than fizzy sugary drinks and fruit juices would be a great starting point. To address the non-obvious sources, which account for the other 20% of added sugars, learning to read a food label would be beneficial, rather than trying to avoid them altogether. It is also very important to note that added sugars have their place in healthy eating and play a bigger role in food other than just taste. Sugar and jams can be used sparingly to sweeten cereals such as porridge, stewed fruit, and wholemeal breads, as a means to help make high fibre, nutrient rich foods more palatable. Sugars also enhance the texture of some food, inhibit crystallization in frozen products, and play a role in food safety by stopping the growth of bacteria.

Analysing the sugar content of food also presents its own challenges. For a start, there is no way to analytically distinguish between added and naturally occurring sugar in the food product. This is yet another reason why using a percentage of total calorie intake for total sugar intake is a better option than trying to account purely for added sugars. There is no evidence to suggest that an excess of calories from one form of sugar over the other is worse.

An excess is an excess regardless of whether it is naturally occurring or added.

When reading a food label, look out for forms of sugar (sucrose, fructose, glucose, sugar, maltodextrin, corn syrup, etc.) listed near the top of the ingredients list. The further up the list then the greater the sugar content. It is not as straight forward to say avoid foods that have Xg of sugar per 100g of product because it depends on how much product you consume. Rather than honing in on the negatives, a better way to look at it is to focus on including plenty of whole and unprocessed foods in your diet most of time, such as lean meats, fish, veggies, fruits, low-fat dairy, nuts, seeds, beans and whole grains. Then some of the time, a drizzle of honey over your oats, a dollop of sweetened yogurt, or a sprinkle of table sugar in your tea is not going to be a problem when consumed as part of a healthy balanced diet.

Instead of trying to source “healthy” sugar alternatives, just moderate your use of it. The type of sweetener that you choose to use should be determined by your personal taste and preference and not just because you perceive it as being “healthy”. Maybe try swapping out nutrient less sources of sugar for more nutrient dense sources. Naturally occurring sugars in their native form from fruits and vegetables such as apples, banana, figs, carrots, and even sweet potatoes, are a better source of vitamins, minerals, phytochemicals, and fibre than their nutrient less counter parts such as table sugar and high fructose corn syrup.

An excess intake of any type of sugar will eventually lead to problems but the occasional treat in conjunction with a healthy balanced diet will do more good than harm.  


  • Erickson, J. and Slavin, J. (2015). Are restrictive guidelines for added sugars science based?. Nutrition Journal, 14(1).
  • Food Safety Authority of Ireland, (2011). Scientific Recommendations for Healthy Eating Guidelines in Ireland. Dublin.
  • Goldfein, K. and Slavin, J. (2015). Why Sugar Is Added to Food: Food Science 101. Comprehensive Reviews in Food Science and Food Safety, 14(5), pp.644-656.
  • Greenwood, D., Threapleton, D., Evans, C., Cleghorn, C., Nykjaer, C., Woodhead, C. and Burley, V. (2014). Association between sugar-sweetened and artificially sweetened soft drinks and type 2 diabetes: systematic review and dose–response meta-analysis of prospective studies. British Journal of Nutrition, 112(05), pp.725-734.
  • Hess, J., Latulippe, M., Ayoob, K. and Slavin, J. (2012). The confusing world of dietary sugars: definitions, intakes, food sources and international dietary recommendations. Food & Function, 3(5), p.477.
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