It is not really losing weight that matters. You can lose weight on any lower calorie diet wherever you lose the calories from, be it carbs or fat.No doubt lots of people have successfully lost weight on low carb, myself included. The question I want answered by trials etc is what happens to people's cardiovascular health when they use low carb with high fat as a long term maintenance diet. By definition they then have to make up the lost carbs with extra fat, over and above the 30% that the eatwell and most other countries' versions of eatwell allow. If they are eating only,say, 20% of their calories from carbs they must be eating a total of 60% of their calories from fat. Diabetics in particular tend to have high levels of atheroma already and I would have thought would be the people least able to risk clogging their blood vessels further with fat. Even monounsaturated fat.