Question

CHO: Why are carbohydrates "demonized" in the media in our era of the KETO diet (formerly the Atkins Diet)? Are all carbs "bad?" What is the function/role of both soluble and insoluble fibers? Discuss the composition and function of both Mono & Di Saccharides.

LIPIDS: Are all dietary lipids "alike?" Saturated vs Polyunsatureated vs Monounsatured vs Trans. What role does fat play in the diet and in the body?

PROTEINS: what are complementary proteins? Complete vs incomplete proteins? What is it's main function(s)?

Answer 1

Carbohydrates are hydrates of carbon. They contain carbon, hydrogen and oxygen as integral parts. KETO diet contains high fat and low carbohydrate. It is due to a notion that carbohydrate increases fat accumulation, leading to overweight and obesity related health issues.  

All the carbohydrates are not bad. There are various types of carbohydrates like mono, di and polysaccharides. Again different types of each of them are needed for the bodily functions. Hence we can not avoid any of them since each is haveing specific function in biological reaction. Excess of glucose intake lead to accumulation if the body does not use it for energy expenditure. This is the real bad thing happening in obese and overweight condition. What is to be taken care is the energy intake should be equal to energy expenditure.

Monosaccharides are the simplest forms of carbohydrates which can not be hydrolysed further. Glucose, the ready source of energy, is monosaccharide. Others include galactose, fructose, mannose xylose, ribose (in DNA and RNA) etc. are essentail for various biochemical reactions. When two monosaccharides join together disaccharides are formed. Lactose in milk is made of glucose and galactose. Sucrose in sugarcane is made of glucose and fructoseAnd so on...

Fiber is non-digestable complex carbohydrate seen in grains, vegetables and fruits. They slow digestion lessening the intake of other food, reduce risk of chronic diseases, support good gut health, maintain a healthy weight, supports the immune system.

Solube fibers absorb water and make the feces to be excreted without constipation. Insoluble fibers constitute bulk or roughage part of the fiber.

All the lipids are not the same. Fat can be simple, complex and mixed. Simple lipids just contain fattyacids. Complex lipids constitute essential parts like glycerol, fattyacids. In addition, they contain phosphate, nitorgenous base, carbohydrates etc. They are triglycerides, phospholipids, glycolipids, etc.

Saturated fattyacids does not contain a double bond in its structure. Mono unsaturated fatty acid contains only one double bond in its fatty acid chain. Poly unsaturated fatty acids contain more than one double bond in fattyacid chain. Unsaturated fatty acids are good for health since its melting point is less than that of body temperature. It gets depleted fast and prevents accumulation in the body. Trans fat is not at all good for health