Scientists and the government gets things wrong all of the time, to which as a consumer and as a human being, we must always be vigilant in recognizing that not everything that we are taught, is the truth. Sometimes, information is wrongly applied, sometimes information is just plain wrong, and sometimes information is misinterpreted, and when it comes to calories, pretty much all of these things are true. A calorie as defined by Merriam-Webster is: "a unit of heat used to indicate the amount of energy that foods will produce in the human body." I suspect that definition, in of itself, will surprise people, who are actually completely clueless about what a calorie is. Now, because the human body is a complicated and masterful piece of work, to which because of the biochemical reactions within the human body when processing food, it is not possible for all foods to be assimilated exactly the same, you come across the basic calorie conundrum.
While the fundamental premise from scientists/government is that a calorie is a calorie that is one of those regrettable half-truths, that is dangerous for all those that do not know the full truth, which is that all calories are not the same, because different calories are treated differently within the human body. To the point, scientists have conducted numerous experiments that measure and test the effect of different dietary restrictions on animals that are similar in biochemical makeup to human beings, to which they have definitely determined that it isn't the caloric quantity or amount that matters, but the substance of the calories themselves.
This means that most diets and exercise programs get it all wrong when it comes to reducing weight, in which the basic belief from these pundits is that to reduce weight comes down to simple mathematics. That is to say, they first determine the normal amount of calorie intake that your body needs to maintain its weight on a daily basis while also possibly formulating a program which adds on some bodily exercise, and then they reduce your daily caloric intake, accordingly. This means, that with lower caloric intake, you will actually lose weight, which is true, and your ability to continue to lose weight or to maintain your weight loss simply comes down to being disciplined, and nothing much more, which is also true. The problem, though, the fundamental problem with this type of approach if it is done to perfection, will be that it typically works for a while, until it no longer works, because the person under this caloric intake reduction program simply can't overcome the constant hunger that they feel within their body.
Instead, when it comes to losing weight and for general good health, one should not be focusing exclusively on caloric intake, but should instead be focusing mainly on the content of the calories. The fact of the matter is that the human body and mind, treats and processes foods differently, based on the food that is being consumed. That is to say, not all calories are equal, because foods are not equal. In order to lose weight then, one needs to reduce their intake of bad foods and bad calories, and to replace them with good foods and good calories. This means pretty much the obvious, that eating ice cream of 500 calories is not the same as eating a steak of 500 calories.
This leads to the point that our food choices do matter, which means that the consumption of foods that have limited or virtually no nutritional benefits should be eliminated or significantly reduced, and instead should be replaced with foods which have known nutritional value.