The cited study is real and correctly identified. PMID 9094871 is Surwit et al. 1997. It compared a high-sucrose diet (43 percent of total daily energy as sucrose) against a low-sucrose diet (4 percent of energy as sucrose) in a six-week weight-loss program. Both arms provided roughly 4606 kJ per day (about 1100 kcal) with 11 percent of energy from fat, 19 percent protein, and 71 percent carbohydrate, in approximately 60 overweight women. The reported conclusion was that high sucrose content within a hypoenergetic, low-fat diet did not adversely affect weight loss, metabolism, plasma lipids, or emotional affect. The paper discloses funding in part from an NIH grant, The Sugar Association, Inc., and the Kellogg Company.

On body weight specifically, the creator's framing is supported. The Te Morenga 2013 BMJ meta-analysis found that isoenergetic exchange of dietary sugars with other carbohydrates produced no change in body weight (0.04 kg, 95% CI −0.04 to 0.13). By contrast, ad libitum reduction of free sugars produced about 0.80 kg weight loss (95% CI 0.39 to 1.21) and increasing sugars produced about 0.75 kg gain (95% CI 0.30 to 1.19). The authors concluded that among free-living people on ad libitum diets, free sugar and sugar-sweetened beverage intake is a determinant of body weight, and that the change appears to be mediated through changes in energy intake.

On outcomes other than body weight, the claim is contradicted. The companion Te Morenga 2014 AJCN meta-analysis of randomized trials on blood pressure and lipids reported adverse effects of higher sugar intake, and the University of Otago release describing it was titled around cardiovascular risk being implicated independent of weight gain. The authors also noted in subgroup analysis that excluding trials funded by the food and sugar industry produced larger estimated effects of sugar on lipids and blood pressure, which is directly relevant given the funding sources of the study the video cites.

Weight-controlled intervention evidence also contradicts the absolute claim. Lustig et al. 2016 substituted dietary added sugar calorie-for-calorie with starch in children with obesity and metabolic syndrome for nine days, holding calories, carbohydrate content, and weight constant. Metabolic parameters improved irrespective of weight change. This is precisely the design the claim says should show nothing.

Dental caries is a category the claim does not address at all. WHO's recommendation to reduce free sugars to below 10 percent of total energy intake (strong recommendation), with a conditional suggestion of below 5 percent, was based on the totality of evidence on both body weight and dental caries. Caries risk is tied to sugar exposure and is not explained by total calorie intake.