A study of four popular weight loss plans showed that dieters lost an average of 11 pounds over two months by following the Atkins plan, while the calorie-counting Weight Watchers method helped people shed more than 10 pounds.
Individuals who followed the Slim Fast Plan and a Rosemay Conley diet plan both lost on average between eight and nine pounds.
Despite claims that the low-carbohydrate Atkins diet could be dangerous due to its reliance on red meat and fat, researchers also found that all the diets tested were healthy.
Helen Truby worked with a team of academics from United Kingdom universities who studied the different diet plans.
She said: "These disappointing findings suggest that people remain resistant to the advice to 'eat more fruit and vegetables', even when they are advised to as part of a modified weight loss programme".
However, the researchers said: "Atkins dieters tended to have a reduction in iron and niacin, probably due to a fall in the intake of cereal and flour, which is fortified in the UK. They also had a generally low intake of dietary fibre overall, which may have implications for bowel health in the longer term".
They also said that popular slimming programmes do result in reduced energy intake while providing enough nutrients.
She described how the randomised controlled trial "provides reassuring and important evidence for the effectiveness and nutritional adequacy of the four commercial diets tested".
The researchers asked 293 people from five regional areas around the UK to keep a diary of their food intake before and during the two-month diet period.
There was also a control group who continued to eat as normal. They found that following any of the four diets did result in a drop in energy intake.
The diets all resulted in a significant drop in body weight compared to the non-dieting controls, but there was no significant difference between the diets in the amount of weight lost.
Based on their results, the authors suggest "commercial companies work in partnership with health professionals to identify high-risk clients and provide them with dietary advice that is tailored to their nutritional requirements".
The study was published in BioMed Central's open access Nutrition Journal.