People with Lactose intolerance don't have enough enzymes to break this down into the monosaccharide pieces of Galactose and Glucose. Instead, tiny microbes get to eat on Lactose, which in turn produce methane gas responsible for other digestional issues.

Sucrose is the molecule that makes up granulated table sugar. Sucrose is a natural 50/50 combo of Fructose and Glucose. Hi-Fructose Corn Syrup (HFCS) is 55% Fructose/45% Glucose. Both HFCS and Sucrose are added in a lot of foods we eat. The huge amount of Fructose we consume in the Standard American Diet (SAD) has been shown to be responsible for a number of our national dietary issues.

Cellulose is polymer of Glucose that plants produce to make their cell well more sturdy and rigid. On the macro scale, this ultimately becomes the hard shelled bark that protects a tree. Humans do not produce the enzyme needed to break down Cellulose into Glucose, so it passes through our digestive system as fiber.

When we consume glucose, our body produces more insulin to compensate for the higher concentration in the blood. The Pancreas secretes insulin into our bloodstream from special islet cells to orchestrate the delicate balance between sugar in the blood and sugar in the cell.

Just remember, nutritional science changes very frequently and everyone works differently, so there is no "best diet," just one that works best for you. While many of us probably eat something similar to the Standard American Diet (50% Carbohydrates), some would prefer to eat Vegan to ease their conscious and others may prefer a high-fat Paleo/Keto approach to food.

Unfortunately for us, our bodies prefer to store these excess calories in the form of fat. Fat requires far fewer calories to maintain and is a fast source of energy for our bodies in a deficit. It requires a massive amount of muscular stress to promote the anabolic production of muscle. 1 pound of lean muscle is 700 calories, while 1 pound of fat is 3500 calories packed into a similar space.

1 lb of fat = 3500 kCal