One study, a researcher added various amounts of sugar to five different dairy products – skim milk, whole milk, half and half, heavy cream, and heavy cream with safflower oil. The point of the various dairy products was that they each had varying levels of fat. Skim milk had almost no fat, while cream and oil contained more than 50% fat.
When people were asked to rate the ones they liked the best, low marks went to the sweetened skim milk (high sugar, low fat), and to unsweetened cream (high fat, low sugar). But when you mix the same amount of sugar into low-fat and high fat products, people prefer the higher fat mix with high sugar.
In other words, it wasn’t just fat or sugar. It was fat and sugar that was addictive.
Another study done on humans, kept male subjects in a ward where their food intake could be measured. For the first few days they were fed a diet designed to keep them at their current body weight (which was around 3,000 calories since they were already overweight). They were given a diet that was 50% carb, 30% fat, and 20% protein.
The participants were then allowed to eat whatever they wished from two free vending machines that contained a variety of things like meats, cheese, bread, cereals, pastries, desserts, french fries, etc. The men were asked to follow their typical eating patterns as closely as possible.
Given the opportunity to eat without restriction, the participants ended up eating an average of 4,500 calories a day. One guy ate almost 7,000 calories. Not only did they over-eat, something interesting happened to their food ratios: they ate a lot more fat (usually coupled with sugar) and less protein. Their fat intake increased to 40 percent, and protein intake decreased to 12 percent.
