As someone who lost 70 LBS 3 years ago without a 'diet' and kept it off, this article strikes me as overly obvious. Anyone who has ever actually seriously lost weight and kept it off knows that everything comes to the bottom line: calories consumed vs. calories expended.
Formula for HN: ((calories consumed - calories expended) / 3500) = weight change in LBS of fat. There are healthy ways to lose and gain weight and there are unhealthy ways, but they all come down to that very, very simple formula.
It's not that simple. For one, you want to lose fat weight, not muscle, bone, etc. weight. How does your body consume or store fat? It depends on available calories, the caloric composition, and your hormone feedback systems. Arguably, the hormones exert more control than anything else.
It gets more complicated from there: hormone's respond to what you eat. Eat more sugar, it raises your insulin (a hormone) which will stop the conversion of fat to energy, and indirectly will cause the conversion of blood sugar to fat. If your insulin is improperly regulated, you'll have difficult following the simple formula above. The same goes for thyroid hormones. They regulate your metabolism. Another hormone involved is cortisol which reponds to stress levels and can increase your blood sugar levels (cascading over into insulin, for example). Note that you can run into the non-intuitive case of over exercise increasing your cortisol causing excessive blood sugar causing fat storage. It's not easy, but it is possible.
One way to look at it simply is to eat foods that control your blood sugar, and manage your stress levels to avoid excessive cortisol. Excessive protein and fiber calories won't cause fat to build, going against the above formula. In fact, protein and fiber are excellent blood sugar regulating foods and are therefore good at controlling fat building.
Simple, yes, but too simple. That formula ignores the fact that (all things being equal) as your weight drops, your basal metabolic rate drops as well. This means that with each pound you lose, it becomes harder to lose the next.
This is why exercise is critical for losing weight. Exercise counteracts this effect by raising the metabolic rate.
That's the thing: It doesn't ignore anything. If your basal metabolic rate drops, that means you are expending less calories through those means. The bottom line remains the same. You'll either need to consume less calories as a reaction, or up your calorie expenditure through increased exercise or through metabolism 'tricks' such as consuming increased (but safe) levels of water.
Let me illustrate what I meant with an example. Based on your formula, if I wanted to lose 10 pounds over 10 weeks, needing a deficit of 514 kcal/day, and my basal metabolism rate were 1800 kcal/day (roughly what mine is), ignoring exercise I would need to maintain a diet of no more than 1284 kcal/day.
How I interpreted your first comment was that you were arguing this would work for the entire 10 week period. My point was that it would not, that over time the rate of weight loss would slow as your basal metabolism rate drops. Given a constant diet, at some point an equilibrium will be reached.
Formula for HN: ((calories consumed - calories expended) / 3500) = weight change in LBS of fat. There are healthy ways to lose and gain weight and there are unhealthy ways, but they all come down to that very, very simple formula.