Why are so many foods advertised as non-fat and cholesterol-free?

This is because food with high content of saturated day and cholesterol can cause different diseases, and to promote that the food is healthy, food advertisers state that their food is non-fat and cholesterol-free.

A common disease is caused because of the high intake of fatty food and food that has high levels of cholesterol, is Coronary Heart Disease (CHD). It is where the coronary artery is blocked by fatty plaques or blood clots. In this way, blood flow to the heart muscles is decreased or even cut off. This may lead to the damage of the cells and eventually the heart may not function.

Well, both latitude and intensity of light affect temperature because, the higher the light intensity, the higher the temperature and since latitude is the measure of how close you are to the equator, then the closer to the equator you are, the higher the temperature is.