The world’s second largest food company Unilever is buying Slim-Fast foods for £1.44bn ($2.3bn).
But the company refused to comment on reports it was also about to buy out fashionable ice cream makers Ben & Jerry’s.
Slim-Fast, best known for its powdered diet drinks, holds 45% of the American markets for health and weight loss foods.
Unilever said this was the fastest growing sector in the US health food business.
Unilever chairman Niall FitzGerald said: “Slim-Fast fits perfectly into our vision for the development of our foods business.
“It brings us a world-class brand and a product range growing at over 20% per annum.”
Unilever recently decided to concentrate on 400 key brands and dispose of a further less profitable 1200 brands.
Its existing range of brands includes the Walls ice cream business, Persil washing powder and Oxo.
The company plans to expand the Slim-Fast brand outside of the US where up until now its sales have been relatively small.