Starch is made of pure sugar and the minute it hits the stomach it BECOMES pure sugar. If the starch is white that means that it has no fiber to slow-down how fast the sugar enters your blood which means your blood sugar will skyrocket, your pancreas will dump a large amount of insulin in a race to lower your blood sugar and over time, you'll likely develop insulin resistance and obesity. Glycemic index explains why starch is bad.
Starch is bad enough but sugar contains fructose that we can only handle in small amounts. Too much sugar causes fructose overload that leads to insulin resistance, leptin resistance and fatty liver problems. The modern food industry has done a very good job of brainwashing us into believing that sugar is a "normal" and healthy part of the human diet. It is not. It never was.
How much trans-fat is too much? ANY amount of trans-fat is harmful. And beware "Nutrition Information Labels". The term "trans-fat-free" doesn't guarantee that it has no trans-fat. The best way to tell if you are getting any trans-fat is to read the ingredients. Watch out for "partially hydrogenated vegetable oil". Trans-fat comes from partially hydrogenated vegetable oil.
Junk fats include saturated fats and omega-6 fats found in cheap cooking or salad oil. Try to use either tree-nut oils like walnut, almond or hazelnut oils OR use extra-virgin olive oil.
What could be dumber than eating until we're full and THEN overstuffing ourselves with sugary fat. Well guess what folks, THAT is what we call dessert. Don't prepare it and certainly don't eat it.