ABC News' Jim Avila reports:

As millions of consumers try to stick to their New Year's resolutions to lose weight, the Federal Trade Commission (FTC) has fined four companies for using false advertising to sell weight-loss and body slimming products.

The agency claims that California-based Sensa Products, LLC, used deceptive language in its commercials that say you can, "Simply sprinkle Sensa on, eat all the foods you love and watch the pounds come off."

"The claims simply aren't supported by the evidence," said Jessica Rich, director of the FTC's Consumer Protection Bureau, of the ads, which helped generate more than $350 million in business for Sensa over a four-year period.

The FTC also claims that Sensa failed to disclose that it compensated some consumers for endorsements and that its creator, Dr. Alan Hirsch, gave endorsements not supported by scientific evidence.

Sensa has agreed to refund $26.5 million to customers and has been ordered by the FTC to back up any assertions that the product actually works.

In a statement to ABC News, Sensa says it "stands behind its product" and has "invested millions in studies to substantiate [their] claims." The company also says, however, that it is making changes in its advertising and will continue to sell the product.

Luxury bath product company L'Occitane was also targeted by the FTC for claiming that its Almond Beautiful Shape and Almond Shaping Delight skin creams have body-slimming capabilities and are clinically proven.

L'Occitane has agreed to refund customers $450,000 as part of the settlement.

In a statement to ABC News, the company said, in part: "As a result of the FTC inquiry, L'Occitane has implemented a set of even more rigorous policies and procedures that will guide future clinical testing and ensure that our marketing and advertising comply with FTC regulations and guidelines."

Two other companies - LeanSpa LLC and HCG Diet Direct - were also targeted in the FTC settlement announced Tuesday.

LeanSpa LLC, which promoted acai berry and "colon cleanse" weight-loss products, will give up $7 million worth of cash and assets. The company is also prohibited from advertising in the future that any of their products can cause fast and significant weight loss unless they have at least two clinical trials to back the claims.

LeanSpa, in a statement to ABC News, described the FTC's tactics as "heavy-handed" and said the company has been "ruined" by the lawsuit.

"LeanSpa was an excellent company with first rank scientific advisors and an excellent, clinically tested weight loss product. It did not mislead consumers in its product claims or billing practices, and was itself a victim of deceptive and fraudulent conduct by its marketing partners. The settlement is a pragmatic compromise which admits no wrongdoing by LeanSpa and Mr. Mizhen and spares them expensive, protracted litigation. Could they have had their day in court, they are confident they and their actions would have been wholly vindicated."

The Arizona-based company HCG Diet Direct, which marketed liquid homeopathic hCG drops for fast and substantial weight loss, has agreed to a settlement that would bar such deceptive claims in the future, according to the FTC.

HCG Diet Direct did not respond to ABC News' request for comment.