believes those sweeteners are helping to fuel an increase in the most deadly disease in america, hearted sdoez. he has a controversial voice for years. >> here is our oral isotope. >> now studies done by kim ber stanhope, a nutritional biologist at the universities of california davis are starting to back him up. she's in the middle of a groundbreaking five-year study which has already shown strong evidence linking excess high fructose corn syrup consumption for risk factors for heart disease and stroke. just calories from added sugars are different than calories from other foods. >> the mantra you hear from most nutritionists is that a calorie is a calorie is a calorie. >> and i think the results of the study show clearly that is not true. sfoo stanhope's conclusions weren't easy to come by. nutrition studies are expensive and difficult. stanhope has paid groups of research subjects to live in this hospital wing for weeks at a time. under a sort of 24-hour lockdown. they undergo scans and blood tests. every calorie they ingest meticulously weighed and prepared. >> they're never out of our sig