Ultra-processed food consumption and the risk of non-alcoholic fatty liver disease—What are the proposed mechanisms?

A high consumption of ultra-processed food (UPF) is a hallmark of Western diets that has been related to increased risk of non-communicable diseases. As an underlying mechanism, UPF may promote non-alcoholic fatty liver disease (NAFLD) which is a key driver of metabolic impairment with extra-hepatic manifestations like type 2 diabetes, cardiovascular disease, chronic kidney disease, and osteoporosis among others. The present review provides an overview of UPF properties that may promote NAFLD and are thus potential targets for reformulation of UPF. Such approaches should address improvements in the quality of carbohydrates and fat, changes in food texture that lower eating rate as well as ingredients that prevent excess caloric intake or avoid dysbiosis and leaky gut syndrome. Promising strategies are enrichment with fiber, prebiotics, phytochemicals, and protein with a concurrent reduction in glycemic load, energy density, saturated fatty acids (FA; SFA), emulsifiers, fructose, and non-caloric sweeteners. Future studies are needed to examine the interactive and protective effects of such modifications in the composition of UPF on prevention and treatment of NAFLD

Expression of the Fatty Acid Receptors GPR84 and GPR120 and Cytodifferentiation of Epithelial Cells in the Gastric Mucosa of Mouse Pups in the Course of Dietary Transition

During weaning, the ingested food of mouse pups changes from exclusively milk to solid food. In contrast to the protein- and carbohydrate-rich solid food, high fat milk is characterized primarily by fatty acids of medium chain length particularly important for the suckling pups. Therefore, it seems conceivable that the stomach mucosa may be specialized for detecting these important nutrients during the suckling phase. Here, we analyzed the expression of the G protein coupled receptors GPR84 and GPR120 (FFAR4), which are considered to be receptors for medium and long chain fatty acids (LCFAs), respectively. We found that the mRNA levels for GPR84 and GPR120 were high during the suckling period and progressively decreased in the course of weaning. Visualization of the receptor-expressing cells in 2-week-old mice revealed a high number of labeled cells, which reside in the apical as well as in the basal region of the gastric glands. At the base of the gastric glands, all GPR84-immunoreactive cells and some of the GPR120-positive cells also expressed chromogranin A (CgA), suggesting that they are enteroendocrine cells. We demonstrate that the majority of the CgA/GPR84 cells are X/A-like ghrelin cells. The high degree of overlap between ghrelin and GPR84 decreased post-weaning, whereas the overlap between ghrelin and GPR120 increased. At the apical region of the glands the fatty acid receptors were mainly expressed in unique cell types. These contain lipid-filled vacuole- and vesicle-like structures and may have absorptive functions. We detected decreased immunoreactivity for GPR84 and no lipid droplets in surface cells post-weaning. In conclusion, expression of GPR84 in ghrelin cells as well as in surface cells suggests an important role of medium chain fatty acids (MCFAs) in the developing gastric mucosa of suckling mice

Appetite Control Is Improved by Acute Increases in Energy Turnover at Different Levels of Energy Balance

BACKGROUND:Weight control is hypothesized to be improved when physical activity and energy intake are both high (high energy turnover, ET). OBJECTIVE:The impact of three levels of ET on short-term appetite control is therefore investigated at fixed levels of energy balance. DESIGN:In a randomized cross-over trial, 16 healthy adults (25.1 ±3.9 y; BMI 24.0 ±3.2 kg/m2) spent 4 x 3 daylong protocols in a metabolic chamber. Four conditions of energy balance (ad libitum energy intake, zero energy balance, -25% caloric restriction and +25% overfeeding) were each performed at three levels of ET (PAL 1.3 low, 1.6 medium and 1.8 high ET; by walking on a treadmill). Levels of appetite hormones ghrelin, GLP-1 and insulin (tAUC) were measured over 14 hours. Subjective appetite ratings were assessed by Visual Analogue Scales. RESULTS:Compared to high ET, low ET led to decreased GLP-1 (at all energy balance conditions: p<0.001) and increased ghrelin concentrations (caloric restriction and overfeeding: p<0.001) which was consistent with higher feelings of hunger (zero energy balance: p<0.001) and desire to eat (all energy balance conditions: p<0.05) and a positive energy balance during ad libitum intake (+17.5%; p<0.001). CONCLUSION:Appetite is regulated more effectively at a high level of energy turnover, whereas overeating and consequently weight gain is likely to occur at low levels of energy turnover. In contrast to the prevailing concept of body weight control, the positive impact of physical activity is independent from burning up more calories and is explained by improved appetite sensations