Despite consistent epidemiological evidence that weight gain is linked to higher fat and lower carbohydrate consumption, supported by animal evidence and the inescapable truth that fat supplies 9 kcal/g compared to 3.75 kcal/g from carbohydrates, low-carbohydrate "Atkins" style diets are heavily promoted for obesity control. The randomised controlled trial evidence is very small. The totality of the evidence continues to show that low-carbohydrate diets are marginally disadvantageous for long-term health and for weight maintenance. People can lose weight equally well on low-carbohydrate ("Atkins-style") diets, and some groups of obese patients tend to lose a little more than on high-carbohydrate groups. This small difference (1-2 kg) may be explained by rapid loss of (glycogen-associated) body water, or by the influence of extraordinary media coverage leading to elevation of expectation and compliance with low-carbohydrate diets in the short term.