Natural sugars are those naturally present in foods such as fruits and vegetables (fructose and glucose) and milk (lactose). The World Health Organization (WHO) states there is no reported evidence of adverse effects of consuming these natural sugars.
Sugars may also be added to foods during preparation, processing, or at the table. It’s the added sugars in the diet we generally need to be concerned about. Consumption of too many added sugars in the diet can contribute to health problems such as weight gain and obesity, type 2 diabetes, and heart disease.
The Dietary Guidelines for Americans 2020–2025 recommends that people two years and older limit sugar intake to less than 10% of total daily calories per day. This means in an adult who consumes a 2,000 calorie per day diet, no more than 200 calories (about 12 teaspoons, or 48 grams of sugar) should come from added sugars.
The American Heart Association goes further and recommends no more than 100 calories (about 6 teaspoons or 24 grams of sugar) of added sugars per day for most women and no more than 150 calories (about 9 teaspoons or 36 grams of sugar) of added sugars per day for most men.
What Are Added Sugars?
Added sugars are those added to foods during preparation, processing, or at the table. Added sugars may include:
- Table sugar
- Brown sugar
- Syrups
- Maple syrup
- Corn syrup
- High fructose corn syrup
- Malt syrup
- Molasses
- Honey
- Sucrose
- Dextrose
- Sugars from concentrated fruit or vegetable juices
- Coconut sugar
- Invert sugar
- Turbinado sugar
- Raw sugar
- Agave nectar
- Evaporated cane juice
- Cane crystals
- Crystalline fructose
- Maltose
From 
https://www.hsph.harvard.edu/nutritionsource/carbohydrates/added-sugar-in-the-diet/
https://www.cdc.gov/nutrition/data-statistics/added-sugars.html
https://www.who.int/news/item/04-03-2015-who-calls-on-countries-to-reduce-sugars-intake-among-adults-and-children