In the last decades the metabolic syndrome (MS) has become one of the most important pathologies and cause of death in industrialized countries. According to the WHO, the MS is characterized by abdominal obesity, dyslipidemia, hypercholesterolemia, artery hypertension and insulin resistance. Perspective studies carried out in Italy show that about 19% of people over 45, not suffering from diabetes, could be suffering from the MS. From a deep analysis of this pathology it appears that obesity is the main predisposing factor of the MS. The excessive increase of body fat and in particular of visceral fat is correlated to the appearance of many pathologies, among which insulin resistance.
The adipose tissue can in general be considered as an endocrine organ which secretes chemical mediators by which it is in turn influenced and, among these, there are certain hormones which influence its accumulation or decrease. Cortisol, for instance, determines the increase of fat, not only visceral, in the central area of the body and it also interferes with other hormones such as GH and testosterone, besides fostering insulin release by the pancreas, thus creating insulin resistance.
In the randomized study “VARIATION IN BODY COMPOSITION AND FAT LOCALIZATION IN RELATION TO TESTOSTERONE CORTISOL AND ESTRADIOL LEVELS,” by A. Angelozzi; M. Spattini, carried out on 50 male subjects, it emerged that testosterone is the hormone which is mostly correlated to visceral fat (p<0.03). Therefore, low levels of this hormone are associated with a greater amount of visceral fat. Instead, as far as cortisol is concerned, no significant correlation was found, although there are many studies which associate high cortisol levels with the increase of visceral fat. In the specific case of this study we must keep in mind that the subjects with high cortisol levels and normal levels of visceral fat also presented very high testosterone levels, therefore it seems that testosterone is the most determining hormone in men as far as visceral fat is concerned. With aging there are hormonal modifications such as testosterone and GH decrease, and insulin and cortisol increase. These hormonal modifications contribute to the increase of visceral fat, thus starting a cycle which fosters the metabolic syndrome. The only way to invert this process is to lose weight and above all visceral fat, which is not easy, since hormonal modifications, which are the cause of fat increase, are also factors that slow down the physiological response to weight loss stimuli. Therefore, it is more than ever necessary to adopt a lifestyle that can balance the correct metabolic functionality altered by unhealthy and dissonant evolutionary signals.
The chronohormorpho diet or “COM diet” has the aim of reducing body and also visceral fat. To achieve this end, it has been suggested to move the calorie intake deriving from carbohydrates to the evening meal, since carbohydrates increase serotonin levels and therefore melatonin levels, and favour an improved physiological sleep and also a reduction of hypercortisolemia in the morning and of hyperglycaemia, which is common in hyperlypogenetic subjects who present an accumulation of android fat, that is “apple-shaped”.
A 2011 study (Greater weight loss and hormonal changes after 6 months diet with carbohydrates eaten mostly at dinner. Solfer S., Eliraz A.) was carried out on 78 Israeli policemen with a body mass index over 30. They were divided into 2 groups and were submitted to two different diets: the first group was given a Mediterranean diet with carbohydrates subdivided in the daily meals, while the second group followed a diet in which over 70% of the total carbohydrates were included in the evening meal.
The results showed that in the experimental group the improvements both at anthropometric level (BMI, abdominal circumference) and at hematochemical levels (IL-6, leptin, adiponectin, LDL, HDL) were significantly higher compared with the control group.
The authors of this study believe that these results, in the group who received carbohydrates at dinner, were due to a greater production of adiponectin which is an anti-inflammatory hormone, which explains the decrease of inflammatory markers and the improvement in insulin sensibility. Moreover, the stimulus of leptin, which is an anorexiant hormone, due to the insulin peak provoked by the evening dinner rich in carbohydrates, should favour a higher leptin level during the day, which would result in eating a minor amount of food.
The problem is that these subjects, above all if obese, present also leptin resistance and therefore the possible leptin increase does not have the desired anorexic results. At this point a consideration comes spontaneous: even if the key to this study were leptin stimulation, as the authors suggest, and considering that its effect is mainly on appetite modulation – which has a fundamental role when following a diet protocol – this does not justify the fact that the subjects who had carbohydrates for dinner and who received the same amount of daily calories (1300- 1500) lost more weight compared with the ones who had carbohydrates in the meals throughout the day. Cortisol sets in here: these obese subjects probably belonged to the hyperlypogenetic morphotype characterized by android obesity type with prevalent activation of the hypothalamus-hypophysis- suprarenal axis and therefore greater production of cortisol. Moreover, carbohydrates foster serotonin production and, as a consequence, of melatonin production, which has an inhibiting effect on cortisol production. This is not irrelevant although someone might say “I don’t mind being hungry on a diet if I get a result in the end”, but the problem is that chronic “appetite” generates chronic stress, and cortisol secretion induced by chronic stress favours an even greater increase of abdominal visceral fat rather than subcutaneous fat. Without doubt in hyperlypogenetic subjects who tend to be cortisol –responder-stress correlated, this mechanism is particularly effective.
L’Accademia del Fitness-Wellness-Antiaging – July 2014