There are vast differences of opinion as to what is the upper limit of fats coming from healthy foods in the plant-based diet.
John McDougall — He recommends less than 10%.
Dr. Fuhrman — He advises against a low-fat diet and recommends more nuts, seeds, and avocado.
T. Colin Campbell – He recommends less than 10%.
Dr. Greger – He says that the research shows that nuts, seeds, and avocados are healthy and their consumption should be encouraged.
When we look at all the different approaches in the plant-based world, the recommendations range from less than 10% to up to 30% or so.
By analyzing the bulk of the research on fat and health, I don’t think we can come to any definite conclusion that there is an exact percentage of fat in the diet that is ideal for everybody.
An extremely low-fat diet (less than 10% of total calories) is often recommended to people with heart disease. It has also been used to treat acne, although it doesn’t work in every case.
But at the same time, not consuming any nuts, seeds or avocados can lead to other problems: low libido, skin problems, and constant hunger.
I think that you have to experiment a little and discover the optimal amount of fat for you. What’s important is to move away from refined sources of fat (oils) and try to eat mostly whole food sources of fat.
After years of controlling my fat intake, I now simply eat all the nuts and seeds or avocados I care to eat and don’t calculate any percentage anymore.
I’m not particularly drawn to eating nuts so that’s no more than one ounce per day. But I do like some nut butters a few times a week. I love avocados and often eat a medium one a day (occasionally two!). I also eat coconut products but mostly just when I travel to tropical countries, which is only 1-3 months out of the year.
Now I’m eating a wider variety of plant foods than I was when I was overly focusing on eating a fruit based diet. I also eat beans, soy products (which contain some fat) and some grains (although I try to focus on root vegetables instead) in addition to fruits, vegetables and nuts. I would say that the fat percentage in my diet now is closer to 25%, averaged out over a week.
Experience has shown that when someone eats a very high-fruit diet, they might need to keep fat to a strict minimum to perform athletically at their best. However, while eating a wider variety of whole plant foods, it doesn’t seem that a low 10% fat diet is necessary.
I haven’t seen conclusive evidence that restricting nuts, seeds, avocados or other similar “unrefined plant fats” improves health. It may be very useful for heart disease patients, but so far that seems to be based more on a hunch rather than research. Science seems to be pointing in the direction that those foods are beneficial.
When I restrict fats to a strict minimum (less than 10%), I personally do not get any trimmer. Nor do I gain weight while eating roughly 25% fat. I stay at the exact same weight. However, I find my food much more satisfying when I eat more plant fats.
So it’s still an issue of controversy even among plant-based experts. But the fact that all of those different plant-based programs achieve roughly the same results tells me that it’s probably not a big issue when eating whole foods.
As for oil, a case can definitely be made for its exclusion in the diet.