The human organism has tools to cope with metabolic challenges like starvation that are crucial for survival. Lipolysis, lipid oxidation, ketone body synthesis, tailored endogenous glucose production and uptake, and decreased glucose oxidation serve to protect against excessive erosion of protein mass, which is the predominant supplier of carbon chains for synthesis of newly formed glucose. The starvation response shows that the adaptation to energy deficit is very effective and coordinated with different adaptations in different organs. From an evolutionary perspective, this lipid-induced effect on glucose oxidation and uptake is very strong and may therefore help to understand why insulin resistance in obesity and type 2 diabetes mellitus is difficult to treat. The importance of reciprocity in lipid and glucose metabolism during human starvation should be taken into account when studying lipid and glucose metabolism in general and in pathophysiological conditions in particular.

Patients with COVID-19 infection presents with a broad clinical spectrum of symptoms and complications. As a consequence nutritional requirements are not met, resulting in weight- and muscle loss, and malnutrition. The aim of the present study is to delineate nutritional complaints, the (course of the) nutritional status and risk of sarcopenia of COVID-19 patients, during hospitalisation and after discharge. In this prospective observational study in 407 hospital admitted COVID-19 patients in four university and peripheral hospitals, data were collected during dietetic consultations. Presence of nutrition related complaints (decreased appetite, loss of smell, changed taste, loss of taste, chewing and swallowing problems, nausea, vomiting, feeling of being full, stool frequency and consistency, gastric retention, need for help with food intake due to weakness and shortness of breath and nutritional status (weight loss, BMI, risk of sarcopenia with SARC-F ≥4 points) before, during hospital stay and after discharge were, where possible, collected. Included patients were most men (69%), median age of 64.8 ± 12.4 years, 60% were admitted to ICU at any time point during hospitalisation with a median LOS of 15 days and an in-hospital mortality rate of 21%. The most commonly reported complaints were: decreased appetite (58%), feeling of being full (49%) and shortness of breath (43%). One in three patients experienced changed taste, loss of taste and/or loss of smell. Prior to hospital admission, 67% of the patients was overweight (BMI >25 kg/m2), 35% of the patients was characterised as malnourished, mainly caused by considerable weight loss. Serious acute weight loss (>5 kg) was showed in 22% of the patents during the hospital stay; most of these patients (85%) were admitted to the ICU at any point in time. A high risk of sarcopenia (SARC-F ≥ 4 points) was scored in 73% of the patients during hospital admission. In conclusion, one in five hospital admitted COVID-19 patients suffered from serious acute weight loss and 73% had a high risk of sarcopenia. Moreover, almost all patients had one or more nutritional complaints. Of these complaints, decreased appetite, feeling of being full, shortness of breath and changed taste and loss of taste were the most predominant nutrition related complaints. These symptoms have serious repercussions on nutritional status. Although nutritional complaints persisted a long time after discharge, only a small group of patients received dietetic treatment after hospital discharge in recovery phase. Clinicians should consider the risks of acute malnutrition and sarcopenia in COVID-19 patients and investigate multidisciplinary treatment including dietetics during hospital stay and after discharge.

Background: Intermittent fasting (IF) was shown to increase whole-body insulin sensitivity, but it is uncertain whether IF selectively influences intermediary metabolism. Such selectivity might be advantageous when adapting to periods of food abundance and food shortage.