The devil is in the details, also when it comes to how to organize meals so that they are nutritious and good for keeping the line.

You follow a balanced diet, quite healthy (healthier than the average, that's for sure). Your lunch is an ode to the best nutrition, the envy of your co-workers; always so meticulously packaged, perfect for photographing and uploading to Instagram. You eat healthy and the whole world knows it, but the scale doesn't seem to know it. The kilos don't fall and doubts emerge. But how is it possible to gain weight with such a careful diet, you think. Well, maybe you're making some mistakes despite all your efforts to eat healthy; but don't worry, those mistakes are easy to correct.

The first thing you should know is that "the term fattening is not the most appropriate", according to the opinion of the coordinator of the Clinical Nutrition group of the Spanish Academy of Nutrition and Dietetics and professor at the University Isabel I of Burgos, Néstor Benítez. The expert prefers to talk about weight gain, something that can have different causes. "We can gain by fat, muscle mass and water, and weight gain can occur even maintaining healthy habits," says the dietitian-nutritionist. The reasons are diverse, but in most cases, they are small basic errors, easy to correct when you don't pay as much attention to what you eat and focus on how much and how much you eat.

Nuts, essential but not unlimited

They are a very important food in a quality diet. They are rich in fats - from 30 to 60% of their composition - especially in monounsaturated and polyunsaturated fatty acids, such as omega 3. They also provide a large amount of protein, fiber, vitamins, minerals and bioactive compounds with antioxidant potential. According to a systematic review published in the journal Nutrients, eating nuts "prevents and treats some risk factors related to chronic diseases, such as changes in glycaemic and lipid metabolism, oxidative stress and inflammation.

But "starting from the fact that the recommendations of the World Health Organization establish a caloric intake of 2,000 to 2,500 kilocalories per day for an adult male, and 1,500 to 2,000 for women, 100 grams of raw nuts will provide us 688 kilocalories, 34.4% of the 2,000 daily established," calculates the member of the specialization group in Clinical Nutrition of the Spanish Academy of Nutrition and Dietetics Lorena Enríquez. And going too far with them is the simplest thing: a few each time we get the worm, spread on the salad for lunch and dinner, crushed into powder to replace a refined flour ... They are ways in which we increase their intake without hardly noticing it, and with it, the calories that we would like to limit. It is also useful to know which nuts to eat at any given time: pistachios relieve difficult menstruations and almonds and pine nuts, knee pain.

Beware of oil, a tablespoon are 100 calories

Olive oil is the basis of the Mediterranean diet and a key component in the prevention of cardiovascular disease, but the free bar of liquid gold leads to weight gain. "One of the habits that can go unnoticed is olive oil; a soup spoon contains 100 calories", warns Benítez. Now, stop to think about how many spoonfuls you've taken a day: between the one that goes to the morning toasts, a couple or three to sauté the vegetables, another to dress the salad... and now multiply them by a hundred. Too much, isn't it? "You don't have to stop consuming it, but always controlling the quantity because it causes the calories ingested to shoot up," Benítez stresses. And if the problem is that you have too much oil, you can freeze it.

The dangers that you don't see (but you do smell) from sofrito

The ABCs of healthy nutrition begin by encouraging home-cooked food, real food. The sofrito de bote is thus replaced by chopped onion and grated tomato, poached over a low heat. It's a delight, but it can become a time bomb as we unleash our culinary creativity and add "extras. "You have to prioritize clean cooking that does not incorporate sources of calories, and a sauce too dense adds many, no matter how homemade. This does not mean that it is unhealthy but, for example, sofrito has a lot of oil in it. In addition, with the excuse you can incorporate some animal product that gives off saturated fat and also makes it lose nutritional quality, explains Benítez. The best way to avoid temptation is to opt for baking, steaming and papillote, says the expert. Although it is also true that stopping eating fat will not make you lose weight.

Lorena Enríquez adds that the energy of sauces and dressings "can go unnoticed because it goes in small quantities, but its caloric contribution is very important. For example, mayonnaise contains 685 kilocalories per 100 grams, and taking into account that a spoonful is 10 grams, each one we add to the dish adds 8.5 kilocalories. The same happens with the Caesar sauce: every 100 milliliters contribute 324 kilocalories, that is to say, that each spoonful that we put to the salad contributes 32,4". And light mayonnaise is also fattening.

Completely healthy biscuits don't exist

We all crave a little snack treat, or something sweet after a meal. That's normal. The bad thing is to think that we can find a way to incorporate them into the diet, and that replacing a chocolate palm tree with a digestive type cookie with dark chocolate could be a step in the right direction. But that's not the case; these kinds of products are still being processed loaded with calories. "One hundred grams of digestive type chocolate cookies are 493 kilocalories, 24.6% of the 2,000 established daily. And it is very common to abuse them," explains dietitian-nutritionist Lorena Enriquez. A couple of these delicacies with breakfast and as many with afternoon coffee already add up to half a thousand kilocalories, and whoever has tasted a digestive knows that there are no two without three... It's better to skip them if we don't want to get fat. In addition, palm oil is usually added to this type of biscuits, so they also provide unnecessary saturated fats. This type of oil is also found in cosmetic creams.

Yogurts with bifidus (and a lot of sugar)

Scientific evidence supports the incorporation of probiotics into the diet as health promoters. "The best documented effects occur in intestinal disorders, such as lactose intolerance, diarrhea associated with antibiotics and infectious diarrhea, allergy... and emerging evidence is accumulating on their possible role in other diseases. As consumer awareness grows, probiotics are increasingly popular and tend to represent one of the largest functional food markets. And dairy products, particularly yogurt, remain the most important vehicles for delivering probiotic bacteria to the consumer," says a 2013 study from the Sismanogleio General Hospital in Vrilissia, Athens.

But Benitez says to be careful when choosing yogurt, as some contain up to 20 grams of sugar per unit. Consumers can check the amount on the product's nutrition sheet, but the dietitian-nutritionist believes there is another way to discard yogurt with too much sugar: when it is passed on to the health claims on the packaging. "If the packaging says it has bifidus, it's very natural, it has real fruit and it has double fibre, it's likely to have a lot of sugar," says the expert, although adding those "extras" to yoghurt doesn't necessarily mean more sugar.

Control problems... with the portions

Yes, the homemade fruit salad is very healthy, but you can't eat the rations of five people either. And like this example there are many. "It's healthy to eat five avocados, as it's a fairly healthy fruit and has very good vegetable fats (it wouldn't even raise your cholesterol)," says Benítez. But the calorie count to take into account is the weekly one, not the daily one: eating several avocados every day can shoot up the extra calories, and the unwanted kilos.

The problem is not yours, it belongs to everyone. "There is something fundamental that we cannot lose sight of: today's rations have increased to an unsustainable amount. Every time we put more food rations and when we go to restaurants the dishes are getting bigger, and so it is very easy to lose perspective, "concludes Benitez. However, with a bit of information and good will it is easier to look good in Instagram and even the scale will notice that you know how to control your weight, either a 10 or a 200 euros (which have their differences).