12 Eliminate other dairy including cheese (now you are "orthodox paleolithic")

If you can do step 1, that is about 50% of the benefit and alone a huge improvement on the standard american diet (SAD) By about step 6 you are at about 75% , by step 9 about 80% and at 10 you are at 99% for most people.

Here is the skeleton of the theory:

Insulin is a phylogenetically old hormone. It is a biological messenger that in excess, is metabolically saying the following to your tissue and organs: "Go ahead and store energy, and go ahead and mature, reproduce and die." Excess insulin in humans is linked to diabetes, alzheimer dementia, metabolic syndrome, obesity, coronary disease and cancer.

We did not evolve under conditions of insulin excess. Food was intermittently available and not superabundant like today. Scarcity and famine were frequent everywhere until recently in evolutionary time. Preferred foods were available year round and dense in calories and nutrients. Animal products, including organs and bone marrow of mammals, fish, and invertebrates (insects) were the preferred foods, supplemented by edible plants (not grains) until the dawn of agriculture. Fruit was seasonal and not yet bred for maximum sweetness. Food was eaten less frequently, had lower carbs than the typical american diet which is about 60%, and was supplemented by often involuntary periods of intermittent fasting and lower calories overall.

We are not adapted to chronic hyperinsulinemia. 

We are also not adapted to eating grass seeds, to which we have been significantly exposed for only about 10,000 years. They contain molecules that are specifically designed to discourage consumption, as well as other problematic chemicals.

The diet is not about eating exactly what "cavemen" ate, or killing your own food. It is solely about duplicating what I believe are the key elements of the internal hormonal metabolic milieu that we evolved under from especially less than 1 million years ago to about 10,000 years ago. This is likely to be achieved not by eating specific things, but more by not eating specific things.

Calorie restriction is a severe, uncomfortable way to have low insulin levels and if calorie restricted (starving) your insulin levels can be reasonable even if your carb percentage is high. However, with calorie restriciton you can get muscle wasting, fatigue and weakened immune function. In animal models, calorie restriction increases longevity substantially. Remember the metaphorical message of insulin? It says, "Mature, Reproduce and then Die". This message is attenuated by having low insulin levels.

Is there another way to live in a world of abundant food without being hungry all the time, yet avoiding the risk of immune dysfunction associated with eating grass seeds that cannot even be eaten without mechanical processing and cooking ? 

Yes, you can work your way down this list.