This is an excerpt from Sport Nutrition-3rd Edition by Asker Jeukendrup & Michael Gleeson.
Over the past century, the yearly intake of simple sugars has increased dramatically to approximately 50 kg (110 lb) per person, which is 25 times more than 100 years ago. This change is largely due to increased consumption of soft drinks, but consumption of candy and baked goods also contributes (figure 2.1).
Accumulating evidence indicates that the intake of large amounts of simple sugars is linked to increased risk of obesity and cardiovascular disease, but considerable debate exists about this topic (Gibson 1996; Rippe and Angelopoulos 2016; Slyper 2013). Although sugar consumption is often plotted against obesity rates and a linear correlation is shown, in the last 10 years, sugar consumption has decreased but the development of obesity has not slowed down. Also, the results of studies are not conclusive. Often, epidemiological studies are quoted to support the role of carbohydrate, specifically sugar, in increasing the prevalence of obesity and related diseases. However, a higher sugar intake is often accompanied by higher saturated fat intake and higher energy intake. Therefore, sugar could simply be an indicator of a higher energy intake. A recent analysis of food availability data in the United States confirmed that this is the case. A report by the U.S. Department of Agriculture presented data about the amount of food available for consumption between 1970 and 2014 and estimated what American food consumption was by subtracting food waste. It was found that between 1970 and 2014, food intakes from all major food groups increased (Bentley et al. 2017). In fact, the average total energy intake increased by 474 calories per person; however, most of this increase in energy intake (about 94%) was attributed to an increased consumption of flour, cereal products, and added fats rather than added sugars.
Given that Americans have been eating more and many have sedentary lifestyles (e.g., driving rather than walking or cycling, watching TV, playing video games), it is easy to understand how the obesity epidemic has developed. Carbohydrate and sugar intakes might not be solely to blame, but they are contributing factors.
Figure 2.1 Sources of sugar intake in the Western diet: (a) daily added sugar intake by age group and (b) where different age groups get their added sugar.
Data from UK National Diet and Nutrition Survey Rolling Programme (2008/2009 - 2011/12), published 2014. Available: www.gov.uk/government/collections/national-diet-and-nutrition-survey