Hyperactivity
How often have you blamed a child’s misbehavior on sugar? It’s a common practice. But sugar plays little to no part in a child’s behavior. Several medical studies have found no significant link between sugar intake and hyperactivity.
Source: WebMD: Busting the Sugar-Hyperactivity Myth

Obesity
With only 15 calories per teaspoon, sugar is no more fattening than any other 15 calories. You gain weight by taking in more calories than your body burns for fuel. Carbohydrates (like sugar) and protein supply 4 calories per gram, whereas fats deliver more than twice that—9 calories per gram. Also, carbs and protein are converted immediately into the fuels a body needs, while fats are initially stored in fat cells for later use. Effective weight management depends on the combination of responsible eating and appropriate physical activity.
Source: Sugar Association

Diabetes
Sugar by itself does not cause diabetes. Both Type 1 and Type 2 diabetes evolve from a disruption of the body’s ability to convert blood glucose (commonly referred to as blood sugar) into energy. Starches and sugars – whether originating from foods like potatoes, carrots, corn, strawberries, and watermelon, or from the sugar bowl, are first metabolized to glucose to meet basic energy needs.

Type 1 diabetes is caused by genetics and unknown factors that trigger the onset of the disease; type 2 diabetes is caused by genetics and lifestyle factors. Being overweight does increase your risk for developing type 2 diabetes, and a diet high in calories from any source contributes to weight gain.
Source: American Diabetes Association

Cavities
Bacteria in the mouth break down all carbohydrates – both starches and sugars. This normal process forms acids that can leach minerals from tooth enamel. Sticky snacks like raisins and other dried fruits, and starchy foods like breadsticks, cereals, and potato chips, linger on teeth and prolong acid production even more than most candies. Infants and toddlers napping with a bottle of juice are also at increased risk of cavities.

Dentists advise reducing between-meal snacks and limiting sweet or sticky foods to mealtimes. Regular brushing and flossing, using fluoride toothpaste and mouthwash, and regular dentist visits are the smart foundations for controlling cavities.
Cavities are lessened by a combination of responsible dental care, smart snacking choices – whether sugar, starches, juices, or anything else, and the time of day snacks are eaten.
Source: Sugar Association

Refining
“Refined” is a misunderstood word, especially when it comes to sugar. Somehow, over the years, refined has taken on the meaning of being overly processed and manipulated. In truth, the definition of refined is “to make pure.” The refining process simply separates natural sucrose from sugar cane without bleaching or chemical manipulation. The Sugar Association provides infographics on the manufacturing process.