You said: " Chronic diseases are rampant, people need to eat better. ", which does imply that eating better aka diet would affect chronic diseases. However, when you look at your list:
Mood disorders.
Diabetes.
Heart disease.
Asthma.
Hypertension
First one, born with it; second one, could be born or develop it, my grandmother was born with it; heart disease, can be born or could contract it from multiple sources say German measles-not much that could be done here; Asthma-born/genetic; hypertension that one I will give you is mostly created though not always. So when I look at this, I see many genetic causes, not things people can treat.
Please let me rephrase my statement, and review the things you see.
"Chronic diseases are rampant, most people need to get their priorities in line."
Also, it's not my list, it's the The Agency for Healthcare Research and Quality's list.
Mood disorders are often quite related to exercise and have been shown to respond to proper diet as well. Many other factors come in to play of course, and as such can't be dismissed.
Diabetes is most often diagnosed as Type II diabetes, commonly related to obesity and diet related problems, along with inactivity. Type I is much less common than Type II. According to the American Diabetes Association,
"In 2012, 29.1 million Americans, or 9.3% of the population, had diabetes. Approximately 1.25 million American children and adults have type 1 diabetes." Essentially 1.25/29.1 (or ONLY 4.29% have a Type I), thought to stem from genetic disarray and/or viral infections.
Heart Disease occasionally stems from non-modifiable risk factors, like genetics, but this is more often not the case. "The good news is that your choices can influence your heart health. Through lifestyle changes like smoking cessation, healthy eating, exercise, and managing diabetes, blood pressure and stress, you can greatly reduce your chance of heart disease." I.E,
Lots to be done here.Asthma, though genetic by nature, also has many variable concerns to be dealt with. Better overall health conditions can greatly reduce the onset of asthma attacks, as well as reduce, and occasionally eliminate the symptoms. Keeping one's body in a higher level of fitness and health can often, though generally not entirely, counteract the need for treatment.
Hypertension. We seem to agree.