Can fruit make you fat? “An apple a day keeps the doctor away” is what we have been hearing from our childhood. It is not uncommon to find out parents and elders dishing out statements that are quite common and sometimes statements that they have made up which emphasize on the fact ‘how very healthy all fruits are’. But surprise, surprise! It might not be as true as you might believe. Recent studies and opinions place fructose as one among the bad guys. And guess what – fructose is quite common in almost every fruit. So, does this mean fruits are not good for health? Let’s explore this further and get to know the differences between different forms of sugar.
Understanding Different Forms Of Sugar – Glucose, Fructose and Sucrose
We all use the word ‘sugar’ irrespective of the context. But, technically, sugar can refer to any of these three – glucose, fructose, sucrose. Though they can’t be differentiated by their taste, they all have different properties and are metabolized differently by our body. You might have heard of the terms monosaccharides and disaccharides in your high school years. And if you remember correctly, glucose and fructose are monosaccharides and they are the building blocks of sucrose, which is a disaccharide. As you can guess, a disaccharide is formed by the combination of two monosaccharides with the removal of water.
How are they metabolized?
Our body tries to break down whatever we eat into the form which it is most comfortable in getting the energy from – glucose. This glucose can be immediately burnt to provide the body with the energy it craves for or it can be stored in the liver as glycogen for future use. You can always find glucose circulating in your blood. It is completely dependent on the enzymes glucokinase or hexokinase to initiate metabolism. The enzyme insulin is secreted if the level of glucose in the blood is found to be high as insulin assist the entry of glucose into cells.
The table sugar which we commonly use mostly consists of sucrose, which is derived from the pulp of the sugarcane. The metabolism of sucrose is simple enough. As soon as sucrose enters the body, the enzyme beta-fructosidase catalyses the decomposition of sucrose into its building blocks – glucose and fructose. Glucose is treated in its usual manner. But in this case, fructose is also present. The body will use glucose as its main energy source and the excess energy from fructose, if not needed, will be poured into fat synthesis, which is stimulated by the insulin released in response to glucose.
Fructose is a sugar that is richly present in almost all fruits. Fructose is metabolized in the liver and like glucose relies on the enzyme fructokinase to initiate metabolism. But, unlike glucose, it does not cause an insulin spike and helps stimulate the production of leptin. Now theoretically, dietary fructose might increase energy intake as it does not stimulate high levels of insulin secretion like glucose. Since insulin increases leptin release, lower circulating insulin and leptin after fructose ingestion might restrain your appetite more than the consumption of other carbohydrates and leads to increased energy intake. However, there isn’t any real convincing experimental evidence that dietary fructose ‘does’ increase energy intake. To quote a study conducted by Division of Endocrinology and Diabetes, Department of Medicine, University of Minnesota, MN, USA. – “Fructose that occurs naturally in fruits and vegetables is a modest component of energy intake and should not be of any concern.”
Insulin spikes and fructose
Thus, studies also suggest that fructose in fruits does not produce the same insulin spike that is produced by glucose or sucrose. You would have to consume an excessively enormous quantity of fruits daily before it starts being detrimental to your health. There is no despair that you may be consuming extra fruits as fruits don’t contain unfilled calories. With the immense amount of dietary fiber and the kind of gratification that they offer, the quantity size of your fruit eating is always in the limit. There is absolutely no reason to shun fruits until you are allergic to them or you are on a ketogenic diet. There is no possible way that fruits are unhealthy and they will not lead to intense weight gain. It seems obvious now, right? How can fruits be unhealthy!