Sugar consumption is a driver of obesity. It's very unclear how much it contributes because epidemiology is ridiculously hard.

The British Diabetes Association specifically states that sugar does not directly cause diabetes. It's important (and honest) to emphasize the distinction because this is the opposite of the prevailing view.

Note that I'm not saying it's fine to eat lots of sugar. Sugar is definitely terrible for your teeth and that alone should be enough to stay away. I'm just saying that the article is being intellectually dishonest, and that's wrong even if the conclusion (eat less sugar) is completely correct.

It's an important distinction though. It's possible to consume sugary foods and not be obese. See twinkie diet.

But skinny people get diabeties also...and if you follow a Twinkie diet and manage to keep your calories consistent and not gain weight you will be priming your body for obesity.

All those twinkies have triggered insulin, a side effect of which increases cell size, with significant impact on fat cells. If your fat cells are enlarged from insulin, then you are primed to become obese because your cells are ready to store more than someone who hasn’t been wrecking their body with insulin spikes from twinkies all day every day.

The Twinkie diet and similar diets are straw men. The fact that it is possible to consume high quantities of sugar and not gain weight is not surprising. The reality is that consumption of high sugar foods (especially high sugar low calorie like many sugary drinks) prime you to eat more. There is a causative relationship between consuming sugary foods and consuming too much. This can be overcome with unnatural levels of attention, however this is a fringe edge case and generally not relevant to discussing the broad impact of sugar in western diets.