Actually, that describes what happens in the context of the subject -- weight loss. You use 7700 kCal more than you take in, and about 1 kg of your body mass vanishes. Hardly bones, of course, but fat, proteins and what not.

It is easy to see this loss, and it is often visualized on weird Japanese TV shows about the subject -- people will have a full body MRI scan before/after a diet course and a doctor compare the two scans for the audience. Not very entertaining, but surely educational up to a point.

Also, this isn't magical. The stuff does actually leave your body as CO2, water and other waste products of metabolism of the said 1 kg. It does appear as a 'missing mass' on your weight scale.

Incidentally, losing weight as a result of using more energy than you take in is the reason all those survivors in pictures from Nazi German concentration camps look like fashion models before makeup, they had too little to eat, and too much hard labor, which used up all that body fat they had before Hitler.

And yes, I Godwined this discussion on purpose.

There was a reason that anti-monopoly and anti-oligopoly legislation was created. The idea is that if one participant in he market is stronger than everybody else and can impose conditions, the 'free' in 'free market' is gone, and the outcome is bad for everyone except the monopolist. This is especially true in markets where the monopoly isn't natural, but bestowed by a law, like the copyrights. The logic is also true for monopsonies, i.e. buyers' markets.

Too bad that the government doesn't sue large corporations for violating those laws very often.

Okay, I'll try once again for you, professor Nitpick:

A piece of living flesh form a human body, the said piece consisting of bones, fat, muscle, skin, etc. in the proportions in which they are regularly found in such body; and having a rest mass of 1 kg in the coordinate system attached to the Earth will, when metabolized in the body of a healthy, average human, release approximately as much energy as will metabolizing, by the same organism, of food with energy content of 7700 kCal, as calculated in the database I mentioned further up.

In MKS units, these 7700 kCal will be about 32 megajoules.

Good enough?

How is it 'pretty evident' that a combination of exercise and food that keeps a person fit doesn't exist? On the contrary, as long as your metabolism doesn't differ from that of most people, science has not only established that there is such a combination, they even provide you with the formulas to calculate it yourself.

A body is a very complex system, so the formula isn't an exact law, but that's no limitation of the science behind it. It is hard because of the complexity, not because of lack of understanding of the laws at the base of the process.

Your body's 'hoarding mechanism' is only triggered if you lose more than (roughly) 5% of your body weight over a month or so. If you stay safely within this limit and you're okay.