No, it’s not the calories, or the fat; it’s the properties of the whey protein of dairy, yes, the protein that so many people regard as healthy for exercise, muscle growth, etc. Whey protein has the peculiar capacity to increase insulin levels dramatically in about 20 percent of people, an effect that can completely shut down any hope of weight loss. The only way to test this question is to eliminate dairy completely for a 4-week period; if you lose, say, 8 or 9 pounds, then you are among those with an exceptional sensitivity to this whey protein effect. If nothing happens, then dairy products are not the culprit, and you can add them back (with all the caveats discussed earlier, such as choosing organic, full-fat, etc.).