First we were brainwashed to demonise dietary fat and the media said it would make us fat and give us heart disease. This caused the low fat, high carbohydrate era, which steered us away from eating healthy, nutrient dense foods with dietary fat (especially saturated) like meat, eggs and dairy. We replaced these foods with grains such as breads, cereals and pastas.
However, we are now starting to see that this was in fact quite detrimental, as chronic disease and obesity have sharply risen. Obviously it is not the sole cause for the epidemic but it is certainly a contributing factor. Now, it seems that carbohydrates are the bane of all evil as they will make you fat and give you diabetes.
What we must understand is that carbohydrates as a macronutrient is not intrinsically bad for your health. It has more to do with the type of carbohydrates. Whole-food carbs such as sweet potato, potato, rice, whole-grains, beans, lentils and fruit are nutrient dense sources of carbohydrates. Whereas processed and refined carbohydrates such as pastas, biscuits, baked goods, fried food and confectionary (sugar) etc. are nutrient void, high calorie carbohydrates that may function very differently in your body compared to whole-food carbs. These processed carbohydrates really become an issue when they become a large part of your diet, rather than the occasional treat.
For weight loss and overall health it would be ideal to minimize the intake of these refined carbohydrates as much as possible as they offer your body very little nutritional value with a high amount of calories, leaving your body unsatisfied and therefore still hungry. Whereas whole-food carbs are nutrient dense and make you feel full for longer.
When individuals switch to a more whole-food, balanced diet, that includes better quality food, especially better quality carbs, they tend to lose weight and improve their health markers. Some studies have even shown that diabetics who are on a moderate carb diet from whole food sources, along with a well balanced diet of protein, vegetables and good fats, seem to improve their blood glucose handling. This is because these types of carbs have many nutrients that are extremely beneficial to health and play important physiological functions in the body.
The moral of the story is to not fear carbohydrates as a nutrient. Source your carbohydrates predominantly from whole-food sources and you will be fine.