WASHINGTON — “Get a gym body without going to the gym” by sprinkling a powder on your food. “Significantly slim your thighs and buttocks” using an almond-scented cream. Lose up to one pound a day with just two drops under the tongue.

Such claims were too good to be true, according to the Federal Trade Commission.

On Tuesday, the commission charged four companies with deceptively marketing weight-loss products, asserting they made “unfounded promises” that consumers could shed pounds simply by using their food additives, skin creams and other dietary supplements.

The four companies — Sensa Products, L’Occitane, HCG Diet Direct and LeanSpa — will collectively pay $34 million to refund consumers. They neither admitted nor denied fault in the case.

The case is part of a broader crackdown on companies that the government says “peddle fad weight-loss products.” Linda Goldstein, the chairwoman of the advertising and marketing division at the law firm Manatt, Phelps & Phillips, said the settlements made clear that the commission would accept only double-blind, placebo-controlled studies to document the medical effectiveness of diet regimes.