Q. I have read in some nutrition websites a couple of times that although a handful of nuts per day is good, nut butters (e.g. peanut butter) are not good to eat often. What is the explanation please?
A. There are a couple of possibilities.
1. One reason is simply due to the extra fat in many nut butters. Take your average supermarket peanut butter. Read its list of ingredients and you'll generally find that it contains only 85 per cent peanuts and the rest is 'vegetable oil'. This is some sort of hydrogenated/trans fat which keeps it smooth and spreadable. Otherwise the oil would separate out and rise to the top. You would need to stir it up each time you used it - like the old-fashioned peanut butter I remember as a child. Nothing wrong with this type of 100% peanut butter - it's all nuts! And better quality. You can buy these at healthy food stores or Sanitarium make a nice one. It's unsalted too which gives it a more interesting flavour, in my opinion.
There is some research however that shows that eating peanut butter also reduces your risk of developing type 2 diabetes. So I don't think we should avoid it. Just buy the better quality.
2. Another reason is that whole nuts have a more fibrous structure that 'traps' some of the nut's natural oils and excretes them. Studies have highlighted a difference between how much fat and kilojoules are measured in nuts in the laboratory (and on food labels) and how much is actually absorbed into the body. Nut eaters tend to excrete more fat in their stools - anywhere from 5 to 15 per cent according to research. Interestingly the more you chew and grind down nuts, the more fat is absorbed and the less fat excreted.
So that is why nutritionists now advocate eating nuts whole rather than as nut butter - you actually absorb less of their oil and you can manage your weight more easily. This also explains why many nut eaters don't have problems with their weight.