You can find all this data on the National Nutrient Database for standard reference, a great source for nutrition information. And whenever possible, you should refer to raw nuts – the importance of this is discussed below. Given the broad range of nutritional content of nuts, the categorization of simply being a “nut” is a woefully inadequate classification. For example, some nuts are low in fat and very starchy, like chestnuts, whereas others are high fat and low carb, like macadamia nuts. Most, however, can be incorporated into a healthy diet.

Lowest & Highest Calorie Nuts – There are so many ways to talk about the nutritional content of nuts, so I decided to tackle this by weight, i.e., per 100 grams. This is about 3.5 ounces or roughly two-thirds of a cup on average – a handful. Keep in mind that for some nuts, this is more of a small meal than a big snack. The amount of calories in 100 grams of nuts ranges from 213 for chestnuts all the way to 718 for macadamia nuts – a difference primarily driven by the fat content. The protein and fat in nuts are what have the potential to help you stick to your diet and feel full if you use them in small portions as snacks.

Nuts With The Most Fiber – Almonds have the most fiber (12% w/w, or 12 g/100g) and cashews & pine nuts the least (3-4%). Chestnuts have the most sugar and Brazil nuts the least. Lastly, peanuts, almonds, and pistachios have the most protein (21-26%) and chestnuts the least (2%).

Nuts Vary By Type Of Fat – Protein quality doesn’t vary widely across different nuts, but fat quality does . In terms of absolute amounts (g/100g), Brazil nuts & macadamia nuts have the most saturated fat, where chestnuts have the least. The presence of saturated fat in nuts is not an unhealthy attribute; in fact, it’s probably a good thing because polyunsaturated fats are highly susceptible to become damaged when they’re processed, and nuts are frequently pasteurized or roasted, which is capable of causing said damage.

Technical Note: For example, one study showed that standard roasting procedures significantly increased the trans fat content, the amount of peroxidized fats, and advanced glycation end products in a variety of different nuts. Advanced glycation end products, also known as AGEs, are found at high levels in diabetics and are associated with age-related diseases, Alzheimer’s, cardiovascular disease, and stroke. Further, excess polyunsaturated fats increase the livers susceptibility to injury.

If you can’t find raw nuts or are unsure, stick to those with low polyunsaturated fats like hazel & macadamia nuts, while avoiding those with high polyunsaturated fats like brazil nuts and walnuts. Macadamia nuts are the safest in terms of fat quality. Also, avoid those with the most sugar and carbohydrates like chestnuts and cashews as these can lead to increased AGE production upon roasting.

The essential fatty acid content of nuts (eg, omega-3 & omega-6 fatty acids) should not be a priority in the selection process. If a theoretical optimal ratio of omega-6 to omega-3 fats actually existed, all nuts would be way over it due to their high omega-6 fatty acid content1. Further, in the context of nuts much of the polyunsaturated fat is heat-sensitive and exposed to heat during roasting, and in general, excess polyunsaturated fat increases susceptibility of the liver to damage from a variety of insults. In other words, if you’re having a beer or glass of wine, a bowl of peanuts is not the best choice for a snack.

Low Carb Nuts – If you’re on a low carbohydrate or ketogenic diet, macadamia nuts and pecans are both more than within the acceptable ratio of fats to carbs plus protein (both are >5), however the latter are high in polyunsaturated fats, so check to make sure they’re raw.