You may hear people say that your body doesn't know the difference between an apple and a donut. Sugar is sugar. Yes, and no.
You’ll see certain diet plans tell people to stay away from fruit because of its sugar content as well as some other natural sweeteners such as honey and agave nectar. Umm ok. First off, bullshit. Please show me someone who became overweight from eating too much fruit. So the reason why I say yes/no to sugar is sugar is due to what else you are getting with the source. Let's dissect donuts real quick. More specifically, let’s focus on Dunkin Donuts glazed donut since “America Runs on Dunkin.” The glazed donut consists of 260 calories, 14g of fat, 31g of carbs, 12g which they say is sugar, 3g of protein and 1g of fiber. Vitamin A 2% of daily recommended dose, Vitamin C 0%, calcium 0%, iron 6%. That's what I would call calorically dense and nutritionally low. You essentially get nothing but sugar with a donut and a lot of calories. Having one of these a day puts you a lot closer to your daily caloric need but far from your daily nutritional need, which puts you at a greater chance of overeating on the day.
An apple at first glance looks like it isn't much better. An apple has 95 calories, 0.3g of fat, 25g of carbs, 19g of sugar, 0.5g of protein, 4.4g of fiber. Vitamin A 1%, vitamin C 14%, calcium1%, iron 1%. With an apple you get far less calories. The sugar content however appears to be about the same, if not slightly more, as a donut. However, why I say they're not the same is due to the much higher fiber content in an apple. The fiber helps to slow the absorption of sugar and can subtract from the total amount of calories consumed in an apple. Also, with an apple, you are getting far more vitamins and antioxidants than you would from a donut.
Neither of these are “bad,” but they definitely are not the same. I would 100% avoid having a donut every day, but that has a lot more to do with it being a processed food product with a high caloric count and low nutrients than it does its sugar content. Sugar does not make you fat, though I understand there may be a lot of articles that say otherwise. It is more easily stored as fat than protein, but that does not mean having sugar will make you fat. It's overconsumption of calories that leads to becoming fat. Eating sugar-only or a majority of your calories from sugar (or carbs) will usually leave you still feeling hungry. This can then lead to overeating, malnutrition, and a host of other issues. The problem that happens is not due to sugar, it’s due to the lack of balance in a diet. So, if someone says you shouldn't have any fruit, I give you permission to slap them across the face.
A simple way I like to think of food is to see if they have a low caloric density and high nutritional density. This basically means choose foods that don't have a lot of calories but give you a lot of what you need. It is much harder to overeat these options especially when you are choosing options that natural and unprocessed.
As for agave nectar and honey, the reason people suggest to have that over table sugar is really quite simple. It's not that it's “better” for you since sugar is sugar. However, since they are both perceived as being sweeter than table sugar you don't need to add as much of it to something you are trying to make sweet. Therefore, you are taking in less sugar so it is a “better” option.
Don't you dare take this article as me saying you can eat whatever the heck you want. I am simply saying an apple is much better than a donut, but it is still fine to have a donut every once in awhile. The main focus is to make sure that you are eating a balanced diet of protein, carbohydrates, and fats that consist of a majority whole food products such as unprocessed fruits , unprocessed vegetables, unprocessed meats, poultry etc. Oh, and agua, can't forget agua. If you focus on this plan and make sure to not overeat, you will overtime feel better.