Almost any controlled diet (short of rice-cakes and water) improves health outcomes over what people eat when they're paying less attention.
Almost every controlled diet excludes most of the same extremely suspect foods (high-fructose bonbons, anything out of the smokey, rarely replenished deep-fat frier from hell).
It probably is true that inflammation is the underlying malady. High LDL levels probably exacerbate the negative effects of inflammation. Refined-carbohydrate–rich diets combined with a sedentary lifestyle are known to be inflammatory.
As I recall, studies of hard-working farmers who ate six eggs a day (with bacon) and not much sugar haven't shown unusually high rates of coronary heart disease. Thus I've begun to suspect that the problem comes from overloading the metabolism on two axes at the same time (lipids and carbohydrates) while also tying one-hand to the sedentary-lifestyle bed post.
In paleolithic times, it was possible to gorge yourself (from time to time) on one food group or another (bananas or bison), but rarely both at the same time (and certainly not without taking a long hike at some point either before, during, or afterwards, plus there's no shortage of labour involved in harvesting a side of bison with a stone axe, or spending an entire day climbing banana trees). These days we hang around in coffee shops playing chess, and the forty-move time control rarely elapses without inducing yet another mocha frappe and a "small" serving of cheesecake (it sure looks small beside that sugary 20-ounce drink).
It seems like any one of three corrective actions: elimination of excess sugar (rice cakes are 100% sugar), elimination of excess fat, or a vigorous physical lifestyle has an enormously beneficial effect. I suspect that any change will do, just so long as your metabolism is not confronting the triple-risk zone on a regular basis.
Of course, if they convince you to stay out of all three risk zones at the same time (carbs from green vegetables only, no animal fat, high exercise) your risk of crossing through the triple-risk zone at any point in time goes almost to zero. I tend to think of that as the belt and suspenders and sneakers approach. Or, if you convince someone to achieve a half-hearted three days of out seven compliance on each of those, he or she is probably mostly out of the weeds, as well.
Evolution tends to make us pretty adaptive. Two out of three stress factors poses only a moderate problem. Three out of three stress factors (a condition almost impossible to achieve in our evolutionary history) and now you have a big problem.
Pure approach to at-worst two-out-of-three:
* farming with ox and plow (always work hard, eat whatever you damn well want)
* total elimination of refined carbs (it's not easy to get or stay fat on this diet, unless you've already got metabolic syndrome)
* total elimination of animal fat (combining balanced nutrition with a green lifestyle is now your biggest challenge; almond production requires six-times more water than industrial chicken meat, per delivered ounce)
Impure approach to mostly at-worst two-out-of-three:
* vigorous exercise two days a week (with sustained spurts of 8-10 METs, ya lazy yoga-pant moron)
* complete elimination of sugary beverages (requires moderation of alcohol, too)
* plenty of animal fat, but not in the form of steak and cheesecake dinners (bad fat+ sugar), or all-you-can-eat fettuccine Alfredo buffets (also bad-fat Hoover Dam + sugar Niagara)
Of course, in any controlled study, interventions that ask for the moon have more margin for non-compliance, and that effect will definitely be measured, and found statistically significant.
That doesn't mean that impure moderation doesn't provide 80% of the benefits for 20% of the religious conviction.
But our research is never geared to tell us this.