Buy low, sell high. Eat less, move more.thats 90% of what you need to know.
Sorry, both are wrong.
"Buy low, sell high" is a fantasy, possible only in hindsight.
And as for "eat less, move more", that simply doesn't work, if what you're eating is crap. "Eat food" is a much better piece of advice.
(90% of our nation's food expenditures are for items that aren't actually food. Our largest single source of calories is high fructose corn syrup, and our largest single source of fat is hydrogenated soybean oil - neither of which should be in our diet at all.)
You can eat fresh veggies till you pop and you would be fine (Fresh as in pulling them out of your garden) its the damned "processed" and/or genomodded crap that is causing all the obesity!