Considered for years a food rich in fats and therefore unsuitable as part of a healthy diet, nuts are being rediscovered not only by health specialists such as doctors, nutritionists, and dieticians, who are now recommending it to their own patients, but also by consumers themselves, who are increasingly, and quite independently, building them into their daily diet.
Nuts such as walnuts, hazelnuts and almonds are also known as oily or fatty nuts since they are actually high-fat food and thus very calorific. However, what's often overlooked is that the type of fats found in nuts and its chemical makeup of micro and macronutrients make it a great food for staying healthy.
It has been scientifically proven that conscious consumption of nuts has positive effects on the body. In fact, research published in 2013 in the New England Journal of Medicine suggests that daily consumption of 30 g of nuts protects the body from cardiovascular disease, type II diabetes, metabolic syndrome, and hypertension.
Fats are essential nutrients for the proper functioning of all bodily organs and systems. So it's very important to introduce a fat quota into the diet: the guidelines for a balanced diet suggest that at least 25-30% of the daily caloric intake should be made up of fats. The key thing is to be very careful in choosing the kind of fats you decide to consume.
Fats come in two main types:
- saturated fats – which may be vegetable fats, such as palm oil, or animal fats, such as in butter and lard –should be limited.
- unsaturated fatty acids which in turn are sub-divided into monounsaturated fats (for example, oleic acid in olive oil) and polyunsaturated fats. Among the latter, omega-3 and omega-6 fatty acids particularly stand out. They are also known as essential fatty acids because they are essential for keeping the body healthy and should always form part of the diet as they cannot be produced through ordinary metabolism.
In general, unsaturated fatty acids are considered to be 'good' fats. According to the guidelines, replacing saturated fats by unsaturated fatty acids as part of a balanced diet contributes to the maintenance of normal blood cholesterol levels
The fat content of nuts, combined with fibre and proteins, makes this food an excellent hunger-satisfying snack. And actually it turns out that pangs of hunger quite often felt around mid-morning and/or mid-afternoon are in fact physiological and depend on the diet.
To put another way in simple terms: during the day, the body's cells run out of 'quick fuel', which is made up of circulatory glucose from breakfast or lunch, and need an additional 'top-up' to continue functioning, so the brain sends out a stimulus to the body to ask it to eat some more food.
In this circumstance, eating 30 g of nuts is a great way to have an energy-boosting snack that produces a feeling of satiety without generating the glycemic peaks (sudden increase in blood glucose) that normally occur when eating foods like packaged snacks full of carbohydrates and simple sugars.
Nuts are a low glycemic index food. The glycemic index (GI) indicates the type of carbohydrates in a food and its propensity to raise blood sugar (blood glucose concentration) in comparison with standard foods such as white bread and pure glucose for the same amount of carbohydrates. Foods with a low glycemic index (<55) should always predominate in a healthy diet. A food's GI may be influenced by various factors such as levels of fibre, proteins and fats that contribute to lowering it. Glycemic load (GL) is even more accurate than GI in measuring the glycemic impact of food because it indicates the number of carbohydrates in a specific portion of food. GL is calculated by the formula GL = GI x g of carbohydrates available in the portion/100.
Keeping both GI and GL low in a meal not only helps delay the onset of hunger pangs but also has several positive metabolic effects that help protect the body from the onset of conditions such as type 2 diabetes and coronary heart disease.
In this respect, adding nuts as an ingredient to your main meals can help you get to the next meal without suffering from hunger pangs. For example, yoghurt with mixed nuts, walnuts added to a salad, sliced almonds with soup, or pine nuts in a plate of wholemeal pasta with vegetables can help lower the meal's glycemic index by delaying the onset of feeling hungry. In addition to this, consuming nuts mixed with dried fruit such as mango, pineapple, apricots, raisins , etc. makes the snack tastier while keeping the GI low. This is something, by contrast, which will not happen with 30 g of dried fruit on their own and makes them very valuable when a rapid energy boost is needed (drop in blood sugar levels, hypoglycaemia). In this case, for example, dates are an excellent alternative to a snack or an energy bar, even when doing sport.
It is quite a different matter when talking of prunes which, despite being in the dried fruit category, nevertheless have a low glycemic index (29) and are also the only dried fruit to have obtained a nutritional indication authorized by EU law under Regulation (EU) 432/2012 (relating to health claims on food). Eating 100 g of prunes actually " contributes to the maintenance of normal gut function" because they are a source of fibre (about 7-8 g/100 g, or almost a quarter of the recommended daily quantity of fibre of 30 g).
These general indications are valid as part of a healthy, balanced diet together with an active lifestyle. Each individual has specific needs and even the daily portion of 30 g of nuts may vary depending on the diet, health status, and level of physical activity of each individual. The main thing is, as ever, not to overdo it to avoid those extra calories.
Sources and insights:
Liguri; Nutrizione e dietologia – aspetti clinici dell’alimentazione; Zanichelli; 2018
Ying Bao, Jiali Han, Frank B. Hu, Edward L. Giovannucci, Meir J. Stampfer, Walter C. Willett and Charles S. Fuchs; Association of Nut Consumption with Total and Cause-Specific Mortality; N Engl J Med 2013; 369:2001-11. DOI: 10.1056/NEJMoa1307352
http://www.sinu.it/public/20141111_LARN_Porzioni.pdf
http://www.healthrevolution.it/prugne-disidratate-benefici/