The term low fat is a very broad statement, how low is low? a truly low-fat diet consists of between 10% - 15% of total calories coming from fats. To make that even more comparable, 15g - 40g is a good ballpark figure to keep in mind, I personally sit around the 30 - 45g mark for total daily fat intake, the lower it is the more insulin sensitivity I experience!
A lot of the studies you see that compared a low-fat diet to a normal western diet are not actually a truly low-fat diet, the total daily fat intake is usually well above 50g which certainly wouldn't constitute as low fat, so you have to question the validity of a lot of those studies.
When I add nuts and seeds to my meals, mostly at breakfast time, I like to keep the quantity quite small, roughly 5 grams and have a few different variates mixed together, for example, 5g of sunflower seeds, pumpkin seeds, chia seeds, and almonds.
I am able to keep my total daily fat intake below 50g with the smaller 5gram servings of nuts and seeds.
When I do my food shopping I all ways look for the lowest fat per serve items, especially with sauces, spreads and dips like hummus, beetroot dip, etc because they quite often are a higher fat-containing product, as well as processed and non processed vegan alternatives like burger patties, falafels, tempeh and tofu, I don't bother buying the product if the fat is any more than 5g per serve because all those smaller amounts across the day really add up.
I tend to limit my consumption of those products to only a few days a week and keep my main priority on consuming whole foods in there most natural state, fruits, vegetables, legumes, whole-grains, and potatoes because they naturally contain very low amounts of fat and are most often the better types of fats, polyunsaturated, etc and overall are the best bang for your buck being nutrient-dense foods with all the vitamins and minerals you need to facilitate daily metabolic pathways.