Meal skipping has become an increasing trend of the modern lifestyle that may lead to obesity and type 2 diabetes. We investigated whether the timing of meal skipping impacts these risks by affecting circadian regulation of energy balance, glucose metabolism, and postprandial inflammatory responses. In a randomized controlled crossover trial, 17 participants [body mass index (in kg/m): 23.7 ± 4.6] underwent 3 isocaloric 24-h interventions (55%, 30%, and 15% carbohydrate, fat, and protein, respectively): a breakfast skipping day (BSD) and a dinner skipping day (DSD) separated by a conventional 3-meal-structure day (control). Energy and macronutrient balance was measured in a respiration chamber. Postprandial glucose, insulin, and inflammatory responses in leukocytes as well as 24-h glycemia and insulin secretion were analyzed. When compared with the 3-meal control, 24-h energy expenditure was higher on both skipping days (BSD: +41 kcal/d; DSD: +91 kcal/d; both < 0.01), whereas fat oxidation increased on the BSD only (+16 g/d; < 0.001). Spontaneous physical activity, 24-h glycemia, and 24-h insulin secretion did not differ between intervention days. The postprandial homeostasis model assessment index (+54%) and glucose concentrations after lunch (+46%) were, however, higher on the BSD than on the DSD (both < 0.05). Concomitantly, a longer fasting period with breakfast skipping also increased the inflammatory potential of peripheral blood cells after lunch. Compared with 3 meals/d, meal skipping increased energy expenditure. In contrast, higher postprandial insulin concentrations and increased fat oxidation with breakfast skipping suggest the development of metabolic inflexibility in response to prolonged fasting that may in the long term lead to low-grade inflammation and impaired glucose homeostasis. This trial was registered at clinicaltrials.gov as NCT02635139.

Dietary nitrate consumption may be a useful adjunct in the control of chronic gingivitis.

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 crossover trial, 16 healthy adults (25.1 ± 3.9 y of age; body mass index, 24.0 ± 3.2 kg/m2) spent three daylong protocols for four times 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 (total area under the curve) were measured during 14 hours. Subjective appetite ratings were assessed by visual analog scales. Results Compared with 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 ET, whereas overeating and consequently weight gain are likely to occur at low levels of ET. 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.

Scope Lithium is an important trace element in human nutrition and medicine. Mineral and medicinal waters may represent a significant source of dietary lithium intake. Methods and results The lithium concentration of 360 German mineral and 21 medicinal waters is determined. Based on a systematic screening, three different mineral waters exhibiting low (1.7 µg L−1), medium (171 µg L−1), and high lithium (1724 µg L−1) concentrations are chosen for an acute bioavailability study in male healthy volunteers. In Germany, a north‐east to south‐west gradient of analyzed lithium concentrations is observed in the 381 tested waters. The lithium concentration in the water is significantly correlated with its sodium (r = 0. 810), potassium (r = 0.716), and magnesium (r = 0.361), but not with its calcium concentration. In a randomized cross‐over trial, volunteers (n = 3×10 each) drink 1.5 L of the respective mineral waters, and lithium concentrations in serum and urine are monitored over 24 h. Consumption of the mineral waters with a medium and high lithium content results in a dose‐dependent response in serum lithium concentrations and total urinary lithium excretion. Conclusion Lithium‐rich mineral and medicinal waters may be an important and highly bioavailable lithium source for human consumption.