I am not sure the nutrition and fitness industries are based on heart disease. If anything, they're based on sex drive.
Sure, eating healthy and going to the gym might save your life but the money makers are people who buy expensive supplements and specialist equipment, not those that eat more salad and less beef and walk ten miles every day.
I guess I'd be a data-point against your claim haha. Purchasing beyond meat over red meat, stevia based sodas, signing up to Orange Theory and Spin classes, getting a Peloton, signing up to a gym membership, buying a Keto diet book or magazine, buying an Apple Watch to track my steps and heart rate and remind me to stand up, buying a weight lifting app and program, buying protein powder and easy low calorie snacks, etc.
The casual "exerciser" is a large market and I'd say it boomed in recent years driven mostly by a desire from people to be healthier and live longer, and not so much because they wanted the beach bod. The latter is still part of the equation too I'm sure, but so is the health crave.
Sure, eating healthy and going to the gym might save your life but the money makers are people who buy expensive supplements and specialist equipment, not those that eat more salad and less beef and walk ten miles every day.