352 overweight men and women took part in a six-week controlled trial of seven slimming regimens versus a placebo diet. They were recruited through a popular television programme. The findings showed that three regimens ('Bai-Lin Tea', the 'Grapefruit Pill', and the 'Natural Vitality' pill) were ineffective. Reduction in energy intake either by meal replacement or by dietary modification led to successful weight loss. Commercial slimming clubs were the most effective measures. Television and other media could be used to test other hypotheses with randomisation experiments.