In the US there are very strict rules about labeling something "reduced Fat" or "low fat." Reduced fat means must be 25% less fat than average, and Low-Fat yogurt has 30% fat calories total. When processers take out the fat, they made up for the mouth feel by adding a water/cornstrach mixture and stabilizers. Cheesemakers would use skim milk and a thickener instead of whole milk.
Getting rid of fat is pretty hard to do, so companies use the "light" label to trick people into thinking it's low fat. There are no restrictions on the words "light" or "natural." I've heard that "lighter" sometimes refers to the color. Or they would say "low in saturated fat" and make up for it with cheaper unsaturated canola oil.
Of course only a dedicated foodie with a lot of time on their hands (ie no kids) would look at every label like this.
However, if a low-fat diet was stealthily high in fat, then why aren't all these SADs feeling satiated on lower total calories? Why are they so hungry for carbs? Is it the wheat addiction, or maybe these funny fats don't cause satiety like animal fats do?
Because adding fat isn't always the key to satiety. In fact it can even work the opposite way for many people. Especially when mixed with sugar and other additives that make the food more appetizing. I mean, even if all vegetable oils were replaced with lard it would hardly change anything. Some of the labeling can be tricky but at the same time, labeling something 95% fat free is correct. It contains 5 grams of fat per 100g of food, which makes almost half of it's calories coming from fat.