Not to take value away from your question, but the nature of nutrition and metabolism and the individuality of both would likely invalidate any real data to be derived from the inclusion of kinetics.

For instance, I have been low/no carb for a number of years. If I eat a bolus of carbs I don't have a correlated change in heart rate and my weight/water baseline returns within a day or two. Mind you, even my carb heavy meals are generally starches and not simple sugars (I will have some taters but wont eat cake). If I eat cake then I will notice some physiological impact but that will return to baseline in a couple of days.

TL;DR - Long term studies on diet will always be flawed in the sense that the controls necessary to make broadly relevant observations are prohibitively expensive and the necessary adherence is almost unachievable.