Hi! As the title says, my family has a history of heart problems and diabetes. My grandfather passed away from a heart attack when my dad was in middle school, and my dad also has diabetes.

I am very lousy when it comes to dieting (I blame my fast metabolism there was never any need to diet) but now that I'm getting older I'm starting to realize that I should watch what I eat. Especially because of my family's medical history.

I know the basics such as avoiding junk food, eating my vegetables and whatnot, but are there any other foods that I should avoid or try to eat more of?

I myself don't have diabetes but I would still like to start eating a diet that would help me prevent myself from developing diabetes. Any suggestions?

Ask your doctor for a fasting blood test and that way you will have a better idea.
For diabetics a carb is a carb is a carb (so sayeth my nutritionist) but, for me, vegetable/fruit based ones (except white potatoes) are better than any grain based carb. I stay away from all grains as much as possible.
Look up the glycemic index. Stay away from the high ones, concentrate on the low ones.

For heart problems, avoid salt as much as you can.

Thanks so much for exposing me to the glycemic index! What a nifty tool I'll definitely be using this more often. But the thought of being unable to eat grains as much as I would like is sort of depressing haha

For me, cutting out grains, has made things sooo much easier. There has been a chocolate cake sitting on the counter that DH and Daughter have been working thru for 2 weeks(!!) and it doesn't even call to me - which is really, really, really amazing.
I read the Wheat Belly book and read the http://www.wheatbellyblog.com
and it all makes sense for me.

I suggest seeing a nutritionist, they can work with you to create an eating plan that adresses your needs and concerns.

In the meantime...avoiding salt, sugar, and deep fried foods seems like a good start. Research the benefits of different fruits and veggies, eat a lot of fiber, and drink lots of water. Exercise, I hear, is good for diabetes prevention,

I also have those things in my family. I avoid eating too much sugar, and take fish oil everyday for my heart (usually 2000 milligrams: two triple strength gel tabs). In general, it's best to avoid cholesterol (fatty foods, red meats) and non-natural sugars.