## 4 Discussion
As for the specific effects of food composition on MetS management, most of the evidence reported so far is also related to fruits and vegetables. Fibers in vegetables and fruits are known to have a beneficial physiological effect by slowing down the absorption of carbohydrates, resulting in a more favorable glycemic response [8]. More recently, research focused on the effect of fibers on the microbiota. A high fiber diet increases the diversity and volume of the microbiome, including probiotics that produce short-chain fatty acids (SCFA) during fiber fermentation [27, 35]. With respect to MetS management, butyrate is the most remarkable SCFA, as it seems to be effective in the treatment of obesity and insulin resistance by several mechanisms: it increases insulin sensitivity, pancreatic insulin secretion and leptin secretion, and it has also anti-inflammatory effects [36, 37]. Processed meat products and poultry dishesAccording to Table 5, we recorded a significantly decreasing trend of processed lean meat products in the SWL group. Though we limited the fat content of foods assigned to this set to 23% in line with national recommendations, this set can still contain relatively fatty items. Such foods have been shown to increase the risk of cardiovascular and cancerous diseases in several studies [15, 16, 38]. Current research also suggests that the consumption of processed meat foods increases the risk of obesity, attributed not only to the overall fat content and consequently high energy content of these products, but also to their high saturated fatty acid content and other components as well [39, 40, 41]. Since our study also involved MetS patients, we must mention a recent study involving obese women, in which participants were divided into two groups: metabolically healthy obesity phenotypes (MHO) and metabolically unhealthy obesity phenotypes (MUHO) [42]. The study reported that those consuming more processed meat foods showed a higher likelihood of MUHO phenotypes. Therefore, we can conclude that in this respect, our study generally confirmed the findings of other recent studies. Nevertheless, we also found that the consumption of poultry dishes was correlated with a steeper weight loss slope (Table 4). We can explain this phenomenon if we consider poultry as an alternative to red meats, which, either processed or unprocessed, have been associated with an increased risk of MetS in related studies [15, 16, 28, 43], while poultry, with its low fat and high protein content, was found to support weight loss [43]. Finally, potato dishesWe found the same strength of correlation between the potato dishes set and the WL slope as for the Raw fruits and vegetables set. It is a well-known phenomenon in clinical practice that patients, in their pursuit of weight loss, eliminate starch side dishes, particularly \"the evil potato\". Our findings corroborate the recommendations of the American Diabetes Association's plate method, which suggests consuming 25% of starchy foods in main meals [1, 44]. Recent studies also suggest that the resistant starch content of potatoes is beneficial for the microbiota, thereby supporting weight loss [45]. Finally, the evaluation of data from the Framingham Offspring Study concluded that potato consumption (including fried and non-fried types) did not increase cardio-metabolic risk in middle-aged and older adults [46], further confirming our results. The role of age is substantialOur study found a statistically significant and strong connection between the age and the slope of the WL trend: higher age was a predictor of less successful weight loss. According to the Harris Benedict equation, energy requirements decrease with advancing age for both genders [47]. In general, clinical experience suggests that older obese patients typically face greater challenges in weight loss due to mobility issues resulting from musculoskeletal conditions associated with excess body weight, which often restrict their physical activity and thereby limit their energy expenditure.