What are
Under the term "starchy" various foods and food products are grouped together by the generous presence of starch, the reserve carbohydrate typical of the plant world.
Plants accumulate starch as an energy reserve to face the winter (this is why tubers such as potatoes are particularly rich in it) or to allow the germination of the seed and the subsequent development of the seedling.
Which ones are they
Diet
Nutritional role of starchy foods
If in plants starch is necessary to ensure their survival during the winter, and to allow the germination of the seed, in man it has represented - from the discovery of agriculture onwards - the preponderant energetic nutrient. Once ingested, through saliva, chewing and intestinal enzymes, the starch is broken down, ring by ring, into the individual sugars that constitute it, or into the individual glucose units which - intertwined through linear and branched bonds - give origin of starch. TO
intestinal level, the glucose deriving from starch is absorbed and released into the bloodstream, then used by the cells for the related metabolic processes, or stored as a short-term energy reserve (glycogen deposits in the muscles and liver) or long-term (conversion into hepatic and adipose triglycerides).
Excess and Health
It follows that an excessive consumption of starchy foods over time, especially in the absence of "regular and demanding physical activity, is responsible for overweight, obesity and metabolic diseases such as insulin resistance → diabetes. Hence the advice, too often taken to extremes," to reduce the consumption of starchy foods in your diet when you want to lose weight.
Too many starchy foods, especially if cooked for a long time, refined or industrially processed, have negative effects on blood glucose levels, which rise excessively following their ingestion; this effect, in addition to being potentially responsible - in the long term - for the onset of diabetes, tends to determine a state of well-being, contentment and numbness due to the condition of hyperglycemia and the stimulus on the release of serotonin. Nevertheless, the condition of hyperglycemia an "important secretion of insulin follows, which tends to bring glucose levels back to normal; this biological event causes a negative rebound in glycemic levels (the so-called postprandial reactive hypoglycemia), which stimulates the hypothalamic center of hunger. Thus we enter a sort of vicious circle which - especially in already overweight and sedentary individuals - leads to the new ingestion of refined starchy foods (see below) and to the inevitable weight gain, with all the negative consequences of the case.
Wholemeal starchy foods
It is good to remember that natural starchy sources contain not only starch, but also other nutrients necessary for the plant and for the germination of the seed: proteins, vitamins, mineral salts, unsaturated fats, and fibers. Most of these nutrients are lost in the refining processes, which aim to improve the palatability, digestibility and conservation of starchy foods. Following this practice, however, products are obtained that are rich in "empty" calories, because they are too rich in energy and poor in essential nutrients, such as vitamins and mineral salts.
Hence the fashion, in some respects acceptable, of preferring whole foods, richer in nutrients and more satiating.
Food advice
Ultimately, starchy foods must remain the pillars of human nutrition, not only for the nutritional aspects so dear to nutritionists of the classical school, but also for reasons of environmental sustainability. If we consider the increasingly widespread "hit and run" eating habits ", it is very necessary - to reduce the" incidence of so-called "diseases of well-being" (obesity, diabetes, etc.) - first of all to moderate the quantities of starchy foods, to give more space to fresh vegetables and lean proteins, and to prefer, at least in a daily meal, whole foods to refined ones.
The "modern" Mediterranean diet fails because in its original concept, typical of the post-war period, it was inserted in a context of caloric poverty and regular physical activity; today the Mediterranean diet, which is based on the prevalent consumption of starchy foods, but also of fish, lean proteins and vegetable oils, is so much criticized because it is inserted in a context of hyperalimentation (too many calories!) in which we eat by dint of snacks and various cereals, exaggerating the quantities and preferring the latter to fruit, fresh vegetables, lean proteins and "good fats", such as those of fish or olive oil.
Last but not least, a sedentary lifestyle further aggravates the problem: just think that the diet recommended for marathon runners, who are notoriously rather thin and lean, provides for a much more consistent and preponderant intake of starchy foods than the rest of the population.
