Not eating anything, and only eating proteins and fats, are both difficult for me. And simply abstaining is actually easier. When I consume anything I begin craving not only carbs, but craving the stimulation of eating, period.

I think its finally uncontroversial to say that not all calories are the same. But eating is more than just the metabolic process; like smoking it's about the physical habits and stimulation. In that way eating chips is not much different than eating pork rinds, and for some people that's what matters most.

Remember the Master Cleanser and juice fast fads? People consuming nothing but raw sugar for days, weeks, and even months on-end derived similar benefits--weight loss, improved insulin sensitivity, etc. And for some people it was really easy because you could sip on your drink constantly throughout the day, which was in an important way the antithesis of abstinence. Not all calories are the same, but it's still the case that fewer calories are better. Just do whatever it takes to get you to fewer calories.

I'm not trying to equivocate diets--vitamins, minerals, and fiber still matter. But, again, calorie count is ultimately the most important metric. How you manage it is largely a matter of your personal tastes and lifestyle. Few people can manage a perfect diet, but there's a least bad diet for everyone, and they're often wildly different. And that's basically what the expert stated in the article--the powdered diet isn't for everybody, but it was important to begin offering alternatives to the "balanced diet" recommendations.