Here's the bit from The Diet Doctor again, about why dairy (and also nuts) could interfere with weight loss:
^11. Eat less dairy products and nuts
Can one eat as much as one likes, and still lose weight? Yes, it tends to work just fine with a low-carbohydrate diet, as appetite regulation happens effortlessly.^
However, despite the fact that a low-carbohydrate diet generally makes it easy to eat just enough, there are foods classified as low carb which become a problem in larger quantities. If you find yourself having a hard time losing weight on a low carb diet, you could try to be more careful with:
Dairy products (yoghurt, cream, cheese)
Nuts
Dairy products all contain a varying amount of lactose (the milk sugar), which slows down weight loss. What’s more, part of the protein in milk generates an insulin response, which can have the same effect. Consequently, cutting back on dairy products may accelerate weight loss. This applies especially to dairy products typically lacking in fat, such as regular milk and different yoghurts, but be careful with full-fat dairy such as cream and cheese all the same.
Exempt from all these dairy product warnings is butter, which is almost pure fat. Butter may be consumed liberally as desired.
Nuts, which are the second food to watch, contain a fair amount of carbohydrate, and it’s very easy to unwittingly scarf down large quantities. Cashew nuts are among the worst carb-wise – you’ll find that they contain around 20% carbohydrate by weight. For someone following a strict LCHF diet with a 20 grams of carbs per day allowance, this means that consuming 100 grams (which happens in a flash!) will have filled their daily quota. Peanuts tend to be around 10-15% carbohydrate – not putting them in the clear either
So, for those of you having trouble losing weight: use nuts sparingly. When in a situation where nuts are an absolute must, know that the most harmless ones carb-wise are macadamia nuts (usually around 5% carbs), or Brazil nuts (around 3%).