Coexistence of Food Reward and Carb theories of obesity

Chris Kresser has an interesting post:

Reframing the obesity debate: cause/effect, genetics & robot clones.
His theory of obesity (reproduced below) may not be completely satisfying for people looking for mechanical explanations, but it is certainly not inconsistent with what has been demonstrated empirically.

Modern lifestyle + genetic predisposition = obesity

It really is that simple.

Modern lifestyle includes processed, refined and highly rewarding and palatable foods, excess fructose, unprepared grains (especially flour), industrial seed oils, environmental toxins, sedentary behavior, stress, infections and dysregulated gut flora.

But the modern lifestyle doesn’t cause obesity in all people. I’m sure we all know someone who eats a horrible diet, doesn’t exercise, is under tons of stress and lives a shockingly unhealthy lifestyle – but doesn’t gain a single pound.

That’s where genetics come in.

The current raging debate about the root or dominant cause of obesity seems rather futile given the number of conflating factors and collinearities and even the lack of clear definitions of the terms being used. Can one define obesity rigorously: is it an instantaneous state or a change from some other state; does the definition vary given the individual? If it is not a precise medical condition but rather a societal problem/theme it is hard to understand why food reward mechanisms and carbohydrate mechanisms of obesity cannot peacefully coexist as important contributors and even reinforce each other non-linearly. To many people there are few foods as palatable as sweet pastries, etc.

Even something as simple sounding as the statement 'you can eat as much meat as you want on a low carb diet' means different things to different people. Richard D Feinman recently gave his take on this in terms of satiety on a high fat, low carb diet.

If you have a weight problem, it is likely that you don't stop eating when you are no longer hungry but instead you continue for a number of possible reasons: eg,  you simply enjoy it (food reward),  you are distracted by hard thought, or perhaps are compensating for stress. One could also legitimately interpret 'eat as much as you want' to mean that there is some perfectly efficient diet (macronutrient breakdown perhaps) that would allow for effectively infinite consumption with the body only using what it needs for optimal performance and getting rid of the rest. Or is the statement meant to be true in some impractical limit which may not be nutritionally sound from a health standpoint, but would technically allow for easy weight loss?