Sugar makes so many things in life sweet—cupcakes, chocolate, cotton candy, lemonade! The list goes on…but what is the price we pay for indulgence? Is it worth the myriad health problems that occur as a consequence of excess sugar consumption?
How Much Sugar per Day?
First, it is helpful to understand how much sugar is reasonable to include in your diet. The Dietary Guidelines recommend less than 10% of calorie intake as sugar. For the average person eating 2000 calories per day, this amounts to 200 sugar calories, or about 12 teaspoons of added sugar.
The American Heart Association Guidelines are even more stringent. They recommend a limit for women of 100 calories/day (approximately 6 teaspoons added sugar) and for men 150 calories/day (approximately 9 teaspoons added sugar). “Added” is the key word here because it indicates that naturally occurring sugars in fruits, vegetables, and dairy products don’t count towards the total. However, “added” does not only refer to things like the packets of turbinado sugar you pour into your venti cappuccino. It also includes sugary ingredients in cereal, cookies, soda, and other sweetened snacks and beverages. You can understand why it is easy for the teaspoons to add up quickly and tip you way over the scales of healthy sugar consumption.
Sugar Basics: A Case for Moderation
Let’s review some basics about sugar consumption to understand why we should enjoy it in moderation.
Sugar, or sucrose, is classified as a simple carbohydrate because of its chemical structure and how quickly it is digested and absorbed relative to complex carbohydrates or starches. The ultimate fate of a carbohydrate, whether it’s oatmeal or an Oreo, is to be broken down to the simplest monosaccharide structure (glucose, fructose, and galactose are the three most common).
Glucose circulates in the blood and is delivered to tissues and organs (including the brain) to provide energy by entering a rather complex metabolic pathway called the tricarboxylic acid (TCA) cycle. The concern over simple sugars doesn’t have anything to do with this part of carbohydrate metabolism since every carbohydrate proceeds down the same path once it’s digested and absorbed.
The faster rate of digestion and absorption of the simple carbohydrate leads to a bigger spike in the blood glucose level (BGL) than the response to a complex carbohydrate. The way the body handles an increase in the BGL is to release insulin, which assists in the uptake of glucose into tissues and muscle. When we are young and healthy and active, this process is exquisitely controlled and even a sharp spike in BGL is managed effectively.
Obesity and inactivity are two significant factors that contribute to insulin resistance, and getting fatter and less active also seem to go hand in hand with getting older. Even if a healthy weight is maintained and you keep exercising, eventually there are declines in cell signaling and receptor responsiveness that can dampen insulin sensitivity.
Does Sugar Cause Diabetes?
Probably the most widespread debate is over the relationship between sugar and diabetes. Many people believe that eating lots of sugar increases the likelihood that you will develop type 2 diabetes. The consensus of scientific data does not fully support this notion.
Added Sugars Working Group for the latest Dietary Guidelines identified several cautions and reasons to limit sugar. These include the low nutrient density of sugar (no vitamins or minerals to speak of for the calories consumed), the role of sugar/sugary foods in overweight and obesity, the relationship between sugar/carbohydrate, triglycerides, and heart disease, and the relationship between sugar and dental caries.
The World Health Organization 2015 report on sugar pared the discussion down to its contribution to overweight and dental cavities, primarily because of the strength of data available in these areas. Neither of these comprehensive examinations of the literature found a strong connection between dietary sugar and diabetes.
An epidemiological study found that increased sugar in the food supply was related to a rise in type 2 diabetes, but this association appeared to be due entirely to the relationship between sugar and body weight. In the Women’s Health Study (34,000+ women in a long-term study looking at diet and various health outcomes), level of sugar consumption had no relationship to the development of insulin resistance or type 2 diabetes. In fact, the women who consumed more sugar tended to be thinner and exercise more.
Exercise, particularly endurance aerobic exercise, is a key factor that affects an individual’s “sugar tolerance.” Simple carbohydrates consumed in excess of the rate at which we use them seem to be the root of the adverse metabolic consequences we attribute to high sugar intake. Exercise stimulates the uptake and oxidation of blood sugar and fatty acids into the muscle, which minimizes the challenge of blood sugar spikes and helps regulate energy balance.
Ready for a Sugar-Free Diet?
It is an interesting and challenging experiment to try to adhere to the dietary guidelines recommendation on sugar intake. Many of us will find it quite difficult, maybe even impossible with a diet that relies on prepared foods and sauces. People who have reduced their overall sugar consumption often report that their sensitivity to sweetness becomes heightened, and they find many packaged foods to be unpleasantly sweet. Every individual can find their appropriate level of sugar based on their metabolism, activity level, and food preferences.