For many, nuts are heat pumps to avoid, especially if the goal is to lose weight. With more than 600 calories per 100 grams, and high in fat, they are a nutritional nightmare for those who live counting calories and buying light products.

Today we will see if nuts really make you fat, which ones are the best and how many you should eat.

Are Nuts Fattening?

Nuts are a good example of the mistake of focusing too much on energy balance. Of course calories matter, but their source matters more.

And according to scientific evidence, nuts are not associated with greater weight:

  • Consuming nuts more than three times a week reduces the risk of obesity compared to lower intakes (study).
  • In a study of more than 300,000 individuals, those who ate the most nuts over five years gained less weight.
  • Adding nuts to diets does not increase weight (meta-analysis).
  • Replacing flour-based snacks with nuts helps you lose weight (study).

What is this caloric paradox due to? At the time we saw some factors that explain why the same calories have different effects depending on the food, and nuts stand out for several of them:

  • High satiating power, thanks to its protein, fiber and fat content (study, study, study, study, study).
  • Higher compensation. Nuts make you eat less in other meals, compensating up to 65-75% of the calories ingested (study, study).
  • Greater adherence to diet (study), being accepted by our brain as a pleasant food (study).
  • Low energy absorption. As this study details, chewing increases absorption, but the calories wasted are high in all cases. East effort it can also raise metabolism, increasing caloric expenditure (detail).
Source: The more chewing, the more absorption

For all this, add 300-350 calories daily of nuts does not produce weight gain (study, study, study). But its benefits go far beyond not gaining weight.

Benefits of Nuts

Nuts are potential trees, and they contain all the nutrients necessary for their development, along with a good combination of protein, fat and carbohydrate.

They share a similar nutritional composition, but each stands out for something particular:

  • The almonds they are rich in magnesium and phosphorus. As with fruits, many polyphenols are concentrated in the skin. These polyphenols prevent, for example, the oxidation of cholesterol (study, study).
  • The walnuts they have high concentrations of Omega 3 (ALA) and a little melatonin.
  • The pistachios they are especially rich in potassium and vitamin K, in addition to providing lutein, important for sight (study).
  • The Brazil nuts They are an excellent source of selenium (study, study).
  • All are rich in flavonoids, but pecans, macadamias, almonds and pistachios stand out.

This nutritional richness is expected to be associated with lower mortality, and it is what science reflects.

Let’s start by talking about heart, where attention was initially focused:

  • Higher consumption of nuts is associated with a lower risk of coronary heart disease (study, study, study).
  • Walnuts improve endothelial function in patients with hypercholesterolemia (study).
  • This review summarizes the results of several large studies, where the higher the consumption of nuts, the lower the mortality from coronary heart disease.
Higher intake of nuts is associated with less mortality from coronary heart disease. Source:

But nuts don’t just benefit your heart:

  • Including nuts at least twice a week is associated with a 32% reduction in the risk of developing metabolic syndrome and diabetes (study, review).
  • They increase the levels of antioxidants in the blood (study) and prevent the formation of cancer cells (study, study, study, study, study).
  • Higher consumption is associated with a lower risk of gallbladder stones (study).
  • They appear to slightly improve cognitive function, in mice (study) and humans (study).
  • Almonds and pistachios, especially al eat the skin, they act as prebiotic, improving the diversity of the microbiota (study, study).

Tips for consuming them

In general, the closer a food is to its natural state, the more benefits it will provide. Therefore, whole, unprocessed nuts they are the ideal option. They maximize satiety and minimize caloric absorption.

If you buy them with the shell, even better, because you will consume less. Partly because you have to put in more effort, but also because shell buildup acts as a visual reminder how many you have eaten (study).

What quantity would be recommended? According to the studies, 30-50 grams diaries they do not produce weight gain and provide all the benefits mentioned. Eat the ones you prefer, ideally combined. Do not forget the skin in almonds, hazelnuts and pistachios.

50 grams of mixed nuts

Even toasted and salted provide benefits (study), but present some problems:

  1. Increased caloric content. As water is reduced, calories per gram increase (study). If you eat them toasted, reduce the portion a little.
  2. Risk of oxidation of polyunsaturated fats and loss of antioxidants (study, study).

We would continue with the creams or butters. Nutritionally they are less recommended, showing, for example, a lower capacity to reduce triglycerides (study), but above all provide more calories and produce less satiety. You can include them in moderation, but the risk of overeating is real. If you buy it, let it be 100% dried fruit, without sugar or additives.

Finally, the almond flours or other nuts. They are gluten-free and much more nutritious than cereal flours, but absorbable calories increase (study), especially with very fine flours.

The finer the flour, the more calories are absorbed. Source:

When making flour, antioxidants are also lost (study). If you make desserts or cookies by mixing other ingredients, such as butter or sweeteners, the combination will be especially palatable, surely increasing the total intake. I recommend limiting the flours to specific times.

As always, context matters. If your goal is to increase caloric intake to gain volume, you have more freedom with creams and flours.

Possible negative effects?

When we talk about nuts, two potentially problematic aspects are often mentioned: their low Omega 3 / Omega 6 ratio and his high phytate content. Let’s do a quick review of both.

Omega 3 / Omega 6 Ratio

Both fatty acids are essential and play their role, but health requires a proper balance. We evolved with an O3 / O6 ratio of 1: 1 to 1: 3, while we are currently closer to 1:16 (study). As this ratio increases, health worsens (study, study).

But as always, not only the ratio of these fatty acids matters, but also their origin. The imbalance in our diet has not been produced by a crazy consumption of nuts, but by the increase of a food unknown to our genome: vegetable oils from seeds.

Unlike traditional oils, such as olive or coconut, seed oils require industrial processes and are easily oxidized (detail, study, study), contributing to low-grade inflammation.

What’s more, an excess of Omega 6 can produce Omega 3 deficiencies, let’s see why.

Plant foods include linoleic acid (AL) as the main type of Omega 6 and alpha-linolenic acid (ALA) as a type of Omega 3. But these fatty acids are not directly usable by the human body, who you must convert them to your animal version: arachidonic acid (AA) from AL and eicosapentaenoic acid / docosahexaenoic acid (EPA and DHA) from ALA.

These conversions are low overall (depends in part on your genetics), and they also share metabolic pathways, competing for the same enzymes. Increasing the consumption of AL could further reduce the conversion of ALA to EPA and DHA (study, study), increasing inflammation.

But there are two important aspects that downplay this ratio:

  • If you eat enough animal Omega 3 (EPA and DHA), mainly from fish, the increase in Omega 6 does not seem particularly problematic.
  • The Omega 6 present in nuts is protected by a good amount of antioxidants, reducing your risk of oxidation and not requiring as much Omega 3 to fight it.

For all this, I would not worry too much about the Omega 6 in nuts.

And what about phytates?

Plants want you to eat their fruit, not their seeds. To defend them, they use chemical weapons, mainly phytates and lectins.

Nuts have enough phytates, and their main mission is to inhibit the absorption of nutrients in the animal that eats them, in this case us (study, study, study).

Source: Phytate in foods and significance for humans: Food sources, intake, processing, bioavailability, protective role and analysis

Societies that depend heavily on cereals (especially non-fermented) tend to develop deficiencies due to the action of phytates (study, study, study, study).

However, in the context of a good global diet, which prioritizes foods of high nutritional density, the phytates in nuts are not of concern, and in fact they can be protective.

Phytic acid has a dark side, but also a more benevolent one: it can act as an antioxidant (study), and is even being studied in cancer therapies (study, study, study).

Source: Protection against cancer by dietary IP6 and inositol

In any case, a simple recommendation to minimize nutrient loss is eat the nuts as a snack, thus avoiding stealing nutrients from other foods. At least one study shows better results when eating nuts as a snack, but it is not relevant either.

On the other hand, we know that soaking cereals and legumes reduces their phytate content, but it is not clear that this process has the same effect on nuts (study). Surely it is not worth it.

In summary, if nuts were the basis of your diet, excess phytates could become a problem, but in normal amounts you should not worry. As long as you are not allergic, eat them without fear.