There is little agreement among governments, institutions, scientists and food activists as to how to best tackle the challenging issues of health and sustainability in the food sector. This essay discusses the potential of school meals as a platform to promote healthy and sustainable food behavior. School meal programs are of particular interest for improving public diet because they reach children at a population scale across socio-economic classes and for over a decade of their lives, and because food habits of children are more malleable than those of adults. Current research on the history and health implications of school meal programs is reviewed in a cross-national comparative framework, and arguments explored that speak for the need of a new developmental phase of school meals as an integrative learning platform for healthy and sustainable food behavior. Nutritional, social, practical, educational, economical, political, and cultural perspectives and challenges linked to the implementation of healthy and sustainable school meals are discussed. Finally, the need for long-term interventions and evaluations is highlighted and new research directions are proposed.

Myosin solutions and suspensions have been monitored during heating at pH 6.0 by using dynamic rheological measurements. The storage modulus (G'), the loss modulus ( G ) and the phase angle (6) all showed a marked dependence on ionic strength in the temperature range 25-75°C. The filamentous gels (ionic strength <0.34) displayed a temporary reduction in G' at temperatures between 50 and 60°C, presumably due to denaturation in parts of the rod portion of the myosin molecule. In the same temperature region the concentration dependence of G' changed by a power of 2. The loss modulus also showed a marked concentration dependence, while the phase angle varied with concentration primarily at low (-40°C) temperatures. For the final gels, heated to 75"C, only G' indicated marked differences due to different protein concentrations and ionic strengths; all gels were almost completely elastic (&lo).Adenosine triphosphate was shown to have a pronounced temporary effect on the filamentous gel formed at low temperatures, i.e. on the gel with the highest concentration dependence, while pyrophosphate had no such effect. However, both adenosine triphosphate (or rather its hydrolysis product: adenosine diphosphate) and pyrophosphate appeared to have a small, lasting effect on the heat-gelling ability of myosin: the former a detrimental effect, the latter an improvement.

BackgroundDiet and physical activity apps are two types of health apps that aim to promote healthy eating and energy expenditure through monitoring of dietary intake and physical activity. No clear evidence showing the effectiveness of using these apps to promote healthy eating and physical activity has been previously reported.ObjectiveThis study aimed to identify how diet and physical activity (PA) apps affected their users. It also investigated if using apps was associated with changes in diet and PA.MethodsFirst, 3 semi-structured focus group discussions concerning app usability were conducted (15 app users and 8 nonusers; mean age 24.2 years, SD 6.4), including outcome measures such as motivations, experiences, opinions, and adherence. Results from the discussions were used to develop a questionnaire. The questionnaire, which contained questions about behavior changes, app usage, perceived effectiveness, and opinions of app usability, was answered by 500 Norwegians, with a mean age of 25.8 years (SD 5.1).ResultsApp users found diet and PA apps effective in promoting healthy eating and exercising. These apps affected their actions, health consciousness, and self-education about nutrition and PA; and were also a part of their social lives. Over half of the users perceived that apps were effective in assisting them to eat healthily and to exercise more. Diet apps were more effective when they were frequently used and over a long period of time, compared to infrequent or short-term use (P=.01 and P=.02, respectively). Users who used diet and PA apps, perceived apps as more effective than users who only used one type of app (all P<.05). App users were better at maintaining diet and PA behaviors than nonusers (all P<.05). Young adults found apps fun to use, but sometimes time consuming. They wanted apps to be designed to meet their personal expectations.ConclusionsApp usage influenced action, consciousness, self-education about nutrition and PA, and social life. It facilitated maintaining a healthy diet and exercising more. Diet and PA apps of the future can be further strengthened by being tailored to meet personal needs.

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The heat-induced gelling of ovalbumin solutions (8.2%) has been studied as a function of pH and ionic strength. At low ionic strengths, plots of gel rigidity against pH passed through a maximum on each side of the isoelectric point (PI). The maximum on the acid side had a higher absolute value and occurred at a higher net charge on the protein than the one on the alkaline side. Increasing the ionic strength shifted the two maxima away from the PI. The results suggest that ovalbumin gelling is governed primarily by electrostatic forces.