Potatoes
Potatoes are starchy vegetables that they contain slow carbs. When starches like potatoes are cooked in boiling water or steamed, their glycaemic index (GI) is fairly low, around 50, but when they are roasted or baked at high temperatures, their GI often approaches 90. Temperature also plays a major role when it comes to toxins. Potatoes contain significant amount of amino acid asparagine, which produces acrylamide when heated above 248°F / 120°C in presence of carbohydrates. Acrylamide causes DNA, neurological, and reproductive damage, and is a probable carcinogen. Just so you have an idea, a large serving of fast food fries contains about 80 mcg of it, which is hundreds of times more than the acceptable safe level. So if you want to keep your blood sugar stable and avoid toxins, boiling or steaming is the way to go with starches.
Eggs
Eggs contain a lot of protein in their whites and a lot of healthy fats, vitamins, and minerals in their yolks. If you want to preserve as many easy to digest nutrients as possible it’s best to keep the yolk runny and the white hard. This means that the best way to prep eggs is poaching or soft-boiling them. If you increase temperature and make scrambled or baked eggs you will partially destroy some vitamins and minerals. Going the opposite way, raw eggs might not be ideal either, the human body can use 91% of the protein in cooked eggs but to only 51% in raw eggs.
Meat
When meat is cooked using temperatures higher than 150°C (300°F), carcinogenic substances start forming. That’s why it’s advisable to use a crockpot to slow-cook your meat or use sous-vide and other types of low heat prep. If you love barbecuing, you should always marinade your meat. It has been observed that formation of these carcinogens is significantly reduced when using marinades. You will get best results with ingredients like garlic, beer, red wine, lemon juice or olive oil.
