processing, its value to some consumers is a richer flavor than white sugar. Health effects Sugar industry funding and health information Sugar refiners and manufacturers of sugary foods and drinks have sought to influence medical research and public health recommendations, with substantial and largely clandestine spending documented from the 1960s to 2016. The results of research on the health effects of sugary food and drink differ significantly, depending on whether the researcher has financial ties to the food and drink industry. A 2013 medical review concluded that "unhealthy commodity industries should have no role in the formation of national or international NCD [non-communicable disease] policy". There have been similar efforts to steer coverage of sugar-related health information in popular media, including news media and social media. Obesity and metabolic syndrome A 2003 technical report by the World Health Organization (WHO) provides evidence that high intake of sugary drinks (including fruit juice) increases the risk of obesity by adding to overall energy intake. By itself, sugar is not a factor causing obesity and metabolic syndrome, but rather – when over-consumed – is a component of unhealthy dietary behavior. Meta-analyses showed that excessive consumption of sugar-sweetened beverages increased the risk of developing type 2 diabetes and metabolic syndrome – including weight gain and obesity – in adults and children. Hyperactivity A 2019 meta-analysis found that sugar consumption does not improve mood, but can lower alertness and increase fatigue within an hour of consumption. Some studies report evidence of causality between high consumption of refined sugar and hyperactivity. One review of low-quality studies of children consuming high amounts of energy drinks showed association with higher rates of unhealthy behaviors, including smoking and excessive alcohol use, and with hyperactivity and insomnia, although such effects could not be specifically attributed to sugar over other components of those drinks such as caffeine. Tooth decay The 2003 WHO report stated that "Sugars are undoubtedly the most important dietary factor in the development of dental caries". A review of human studies showed that the incidence of caries is lower when sugar intake is less than 10% of total energy consumed. Nutritional displacement The "empty calories" argument states that a diet high in added (or 'free') sugars will reduce consumption of foods that contain essential nutrients. This nutrient displacement occurs if sugar makes up more than 25% of daily energy intake, a proportion associated with poor diet quality and