Mice with one thyroid hormone receptor (TR) alpha-1 allele encoding a dominant negative mutant receptor (TR alpha1(PV/+)) have persistently elevated serum T3 levels (1.9-fold above normal). They also have markedly increased hepatic type 1 iodothyronine deiodinase (D1) mRNA and enzyme activity (4- to 5-fold), whereas other hepatic T3-responsive genes, such as Spot14 and mitochondrial alpha-glycerol phosphate dehydrogenase (alpha-GPD), are only 0.7-fold and 1.7-fold that of wild-type littermates (TR alpha1+/+). To determine the cause of the disproportionate elevation of D1, TR alpha1+/+ and TR alpha1(PV/+) mice were rendered hypothyroid and then treated with T3. Hypothyroidism decreased hepatic D1, Spot14, and alpha-GPD mRNA to similar levels in TR alpha1+/+ and TR alpha1(PV/+) mice, whereas T3 administration caused an approximately 175-fold elevation of D1 mRNA but only a 3- to 6-fold increases in Spot14 and alpha-GPD mRNAs. Interestingly, the hypothyroidism-induced increase in cerebrocortical type 2 iodothyronine deiodinase activity was 3 times greater in the TR alpha1(PV/+) mice, and these mice had no T3-dependent induction of type 3 iodothyronine deiodinase. Thus, the marked responsiveness of hepatic D1 to T3 relative to other genes, such as Spot14 and alpha-GPD, explains the relatively large effect of the modest increase in serum T3 in the TR alpha1(PV/+) mice, and TR alpha plays a key role in T3-dependent positive and negative regulation of the deiodinases in the cerebral cortex.

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Previous studies have demonstrated that portion sizes and food energy-density influence children's eating behavior. However, the potential effects of front-of-pack image-sizes of serving suggestions and sugar content have not been tested. Using a mixed experimental design among young children, this study examines the effects of image-size manipulation and sugar content on cereal and milk consumption. Children poured and consumed significantly more cereal and drank significantly more milk when exposed to a larger sized image of serving suggestion as compared to a smaller image-size. Sugar content showed no main effects. Nevertheless, cereal consumption only differed significantly between small and large image-sizes when sugar content was low. An advantage of this study was the mundane setting in which the data were collected: a school's dining room instead of an artificial lab. Future studies should include a control condition, with children eating by themselves to reflect an even more natural context.

Persuasive on-pack marketing strategies, such as colourful images and games, affect children's preferences and requests. The purpose of this study was to describe the prevalence of these child-directed (i.e. aimed at children) strategies on food packages at a Belgian retailer. Although previous research already demonstrated the frequency of most of these techniques directed at children, this paper extends to food pricing and facing strategies (i.e. the number of items from the same product aligned next to each other in the supermarket shelves) which were unstudied till now. Moreover, the association between the use of these strategies, the products' (un)healthiness and their type of brand (national vs. private) is investigated. The content analysis found that 372 food products contained one or more child-directed marketing strategies on-pack, all these communications were coded; the products could be classified in 15 food categories. On average, 3.9 (Min = 1; Max = 8) food promotion techniques were used per package. Unhealthiness of products was rated according to Food Standards Agency (FSA) Nutrient Profile UK. We found that 89.2% of all products with child-directed strategies were considered to be unhealthy. The presence of marketing strategies was associated with higher product unhealthiness, but did not differ much between types of brand. Overall, these findings suggest that (unhealthy) foods aimed at children typically feature many on-pack persuasive communications, which implies that policy makers should (continue to) monitor this. These findings highlight the need for further research to investigate the impact of on-pack communications on children's consumption.

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