Sugars aren't all the same. They occur naturally in some foods and are added to many kinds of processed foods.
Examples include sucrose, fructose, high fructose corn syrup, invert sugar, honey, lactose (milk sugar), dextrose and maltose. These sugars are all broken down to glucose and fructose in the body, except for lactose which form glucose and galactose.
All these sugars provide approximately four calories (17kJ) per gram.
What is high fructose corn syrup and what is the big deal?
High fructose corn syrup (HFCS) is a liquid sweetener commonly used by the food industry. It is derived from corn starch and is found in cold drinks, baked goods, condiments and a large variety of processed foods.
It is used to enhance the texture and “mouth-feel” of foods. It also acts as a preservative and assists with moisture retention to ensure baked goods stay fresher for longer. In addition, it helps control the boiling, melting and freezing points of products.
For many years, the question has been raised about whether or not HFCS is more detrimental to health than sucrose (table sugar) and whether it is unique in terms of causing weight gain and obesity. Controversy still exists but, to date, based on research, the scientific community agrees that there is insufficient evidence to conclude that HFCS is any worse than sucrose and other added sugars. Excess of any added sugars is likely to have adverse effects on health.
Added sugars and your health
Added sugars include all sugars and syrups that are added to food during preparation and processing. High intakes of added sugar (irrespective of the type) can contribute to the development of numerous conditions, including tooth decay, inflammation, raised triglyceride levels, non-alcoholic fatty liver disease and cognitive decline.
A higher consumption of added sugars contributes to a higher energy (calorie) intake and lower nutrient intake, which in turn contributes to an increased risk of overweight and obesity, cardiovascular disease, prediabetes and type 2 diabetes. A high intake of foods sweetened with high fructose corn syrup, sucrose or cane sugar may also increase blood uric acid levels and the associated risk of developing gout.
Recommended limits for sugar intake: how much is too much?
Although it is not recommended that people cut out sugar completely, experts agree it is important to limit the intake of added sugar. Numerous respected scientific organisations and public policy makers have put forward recommended upper limits for sugar intake. There is, however, no consensus on what exactly the upper limits should be, and limits range from 5–25% of total daily calorie intake.
According to the American Heart Association, added sugar should be limited to no more than six teaspoons per day for adult women and no more than nine teaspoons per day for men. Remember that this includes the added sugar “hidden” in processed foods. Check foods labels: every 4g of sugar is equal to one teaspoon; for example if a food contains 20g of sugar per serving, it is the same as five teaspoons.
The World Health Organization (WHO) recommends limiting “free sugars” to no more than 10% of one's total daily calorie intake.
The WHO defines “free sugars” as “monosaccharides and disaccharides added to foods by the manufacturer, a cook, or a consumer and sugars naturally present in honey, syrups, fruit juices, and fruit juice concentrates.” According to the WHO their recommended limit does not apply to intrinsic sugars found in whole fruit and vegetables and the sugar in milk (lactose and galactose).
Foods with “intrinsic” or naturally-occurring sugars, such as fresh fruit, are packed with healthy nutrients like fibre, vitamins, minerals and phytonutrients, while foods with added sugars are often highly processed and low in nutrients and provide “empty calories”, i.e. calories without nutritional value. Due to the high fibre content of fruit, it is digested slowly and does not result in significant spikes in blood glucose levels. That said, portions should still be controlled. The recommendation is to eat 2–3 fruit servings a day, with a serving being approximately equal to the size of a tennis ball or one cup of chopped fruit.
What is the bottom line when it comes to sugar?
Overall, a healthy diet can include both naturally-occurring sugars and added sugars. The key is balance and moderation. Excess can cause harm, thus eating a nutritionally balanced diet, while reserving high sugar foods as treats for celebrations and social events and not “everyday” foods, is essential.