Yes. 2000 calories can be starvation, complete with feeling like crap, reduced mental and physical capabilities and the body lowering its metabolism to keep itself from getting thin. Also, even if you do lose weight by starving yourself (which is inevitable if you do eat little enough for long enough and don't die from malnutrition), you can't go back to eating enough to feel satiated, because you'll get fat again. You'll need to feel like you're starving for the rest of your life.
For a 150 pound male who is sedimentary, approximately 2100 calories is required to maintain weight (American Cancer Society). While there are exceptions, most people who are overweight eat too much and exercise too little.
I'm a 155 lb male who does weight training 3 times a week with a personal trainer and if I eat more than about 1500 calories a day, I gain weight (mostly as fat).
When I was completely sedentary, anything more than about 1200 calories per day would cause me to gain weight (entirely fat). And this is with an extremely controlled diet of mostly fresh fruits and vegetables over the course of a year.
I wish I could eat 2100 calories per day. That sounds like such a luxury.
The thermic effect of various foods is so wide that you can have a 30% effective calorie swing based on what you eat. Protein for instance requires about 30% of the calories just to digest it. Fat? 3%
So then diet and exercise are a proven effective way for you to control your weight. Except for the fact that you wish you could eat more. But why do you want to eat more? You can't be feeling "like crap" as anonymous suggested or you wouldn't even be able to train. Maybe you just enjoy food and feel it would be nice to enjoy it more often.
I think that's really where most people are at. With varying degrees of consumption capacity. So the question is, do we want to "fix" ourselves so that we can consume more just because we like to eat? I don't really feel like that's a direction we should be trying to go.
You could eat 2100 calories a day without gaining weight if you expended 2100 calories a day on average.
Weight training does not necessarily burn a lot of calories, particularly fat calories. It primarily depletes glycogen reserves, which are quickly replenished in 1-2 meals and a good night's rest.
There is good evidence that people who seem "naturally thin" actually burn a lot more energy throughout the day by moving in small, maybe unconscious ways:
That's not what I want a citation for (but, yes - even that is not a trivial assertion, given that there is a nontrivial part of the population, perhaps even 10% who do not get fat regardless of the amount they eat)
I want a citation that "exercise and diet" are enough to convert a fat person to a thin person. Trivially, that's true - just stop feeding person until they starve and almost die, and then feed a little.
But the non-trivial question is: Given person X who is now fat (possibly a result of binge eating, but possibly a result of disease, some kind of pharmaceutical treatment, etc.) - can exercising and reducing intake alone make them thin, without damaging their psyche, without limiting their intellectual potential and mental well being?
There is NO reason to believe that the answer is a simple "yes". People who claim that the answer is definitely yes should be able to back their claims easily, if this is so trivial.
No, that's totally not what he claims, although that might be what he thinks he argues.
There are enough data points of (thin person, does not exercise or eat properly) and (fat person, exercises and eats "properly") to make that point basically wrong.
Perhaps the problem is with the definition of "properly". But the causation is not total (that is, there are reasons other than food and exercise that cause people to become fat, some known and some unknown), and the population correlation is time reversed to what you would expect (people stop exercising AFTER they gain weight, not BEFORE), to make this not a trivial matter at all.
Huh? There's a whole section about how the average person can go an entire month without eating at all because eating is not even entirely necessary. One guy went over a year with only water and vitamins and lost over 200lbs. And if I recall correctly from previous reading that guy actually kept the weight off for years. Nothing about a life of continuous starvation and suffering.
People have gained weight on half as many calories.
2000 calories hasn't worked for a lot of people, perhaps because the gut bacteria is too efficient and the body alters their metabolism.