Flax, also known as linseed, is a nutrient-dense and fiber-rich crop with multiple uses. Flax is grown for its seeds, which can be ground into flaxseed meal, pressed into an oil, or spun into linen.Some people believe that flax seeds can be used in your diet as a way to jumpstart or speed up weight loss. Studies on this are conflicting, but there is reason to believe that flax seeds can help some people lose weight.