A lot is written about consuming lesser calories for weight loss. Crash diets, designer diets and what not!
For the one on the path to health a fundamental knowledge may be of great aid.
It is true that one Kcal(what we call as calorie) from whatever source, be it ice cream or burger or salad contains 4184 joules of energy. So far so good.
Ghrelin is an important gut hormone whose hallmark functions are its stimulatory effects on food intake, fat deposition and growth hormone release. It is famously known as the “hunger hormone”. The more the ghrelin secreted, the hungrier you are. However, the functions of ghrelin go well beyond hunger.
When we eat foods containing processed sugars like ice creams and candy, fructose is released in the body. Whereas fructose present in whole fruits is combined with fiber, water and other minerals. Fruits also need adequate chewing. Therefore natural fructose is metabolised by the liver over time and is healthy. However, fructose in processed foods does not have the luxury of other combinations. It provides a sugar spike. More about that later. For now, it is vital to know that consumed beyond a point, fructose from processed foods may cause insulin resistance, abdominal fat gain, blood sugar and so on. Even if we decide to consume identical amounts of calories from processed foods, we may loose only a small amount of weight and a lot of health.
Moreover, processed food fructose leads to higher levels of ghrelin. Hence the person does not feel quickly satiated. You end up eating more after an ice cream with 600 calories than after a very large bowl of fruits and fresh salad containing 600 calories as well. If you want to loose weight, the choice is obvious.
Different foods are processed by the body using different chemicals in the body. For example proteins which typically contain 4 cal per gram require a lot more effort by the body for its digestion. This effort reflects in using energy or thermic effects. Typically fats require around 3% of their calories for digestion and metabolism, carbs require 7% and proteins need 27% of its calories for digestion.
The maths is very simple. If I eat 100 cal of carbs, 93 cal will be left with my body while if I eat proteins, only 77 calories will be left for the use of my body. Hence eating proteins is a better choice for weight loss. Not just that, studies also indicate that a high protein diet boost body metabolism. Therefore high protein diets provide greater metabolic advantage. A boon for weight potential weight losers.
Proteins also satiate the brain centers far better as compared to carbs. Studies have shown that higher protein intake may reduce hunger by upto 30%. Therefore proteins are wonderful for weight reduction.
Refined carbs have what we call as a high glycemic index(GI). This measure how quickly calories are digested and they raise blood sugar. Refined carbs provide a huge spike in blood sugar very fast. It further leads to a sharp fall within hours. This roller coaster of sugar creates a strong craving for another spike or another refined carb snack. Higher GI foods also create upto 80% greater hunger as per studies in teenagers.
It is clear that a calorie from carbs or from Fats or from Proteins or from refined ingredients is just not the same.
Please do make a very informed decision about what you might want to eat. Meats, flour are fine too except if they are refined.