There are few neuropsychological or neuroimaging studies of HIV-positive children with "slow progression". "Slow progressors" are typically defined as children or adolescents who were vertically infected with HIV, but who received no or minimal antiretroviral therapy. We compared 12 asymptomatic HIV-positive children (8 to 12 years) with matched controls on a neuropsychological battery as well as diffusion tensor imaging in a masked region of interest analysis focusing on the corpus callosum, internal capsule and superior longitudinal fasciculus. The "slow progressor" group performed significantly worse than controls on the Wechsler Abbreviated Scale of Intelligence Verbal and Performance IQ scales, and on standardised tests of visuospatial processing, visual memory and executive functioning. "Slow progressors" had lower fractional anisotropy (FA), higher mean diffusivity (MD) and radial diffusivity (RD) in the corpus callosum (p= <0.05), and increased MD in the superior longitudinal fasciculus, compared to controls. A correlation was found between poor performance on a test of executive function and a test of attention with corpus callosum FA, and a test of executive function with lowered FA in the superior longitudinal fasiculus. These data suggest that demyelination as reflected by the increase in RD may be a prominent disease process in paediatric HIV infection.

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The Canadian government recently committed to introduce legislation to restrict the commercial marketing of unhealthy foods and beverages to children. We compared the degree of strictness and agreement between nutrient profile (NP) models relevant to marketing restrictions by applying them in the Canadian context. With the use of data from the University of Toronto 2013 Food Label Information Program ( = 15,342 prepackaged foods), 4 NP models were evaluated: the Food Standards Australia New Zealand-Nutrient Profiling Scoring Criterion (FSANZ-NPSC), the WHO Regional Office for Europe (EURO) model, the Pan American Health Organization (PAHO) model, and a modified version of the PAHO model (Modified-PAHO), which did not consider the extent of food processing because the application of this characteristic was prone to ambiguity. The number and proportion of foods that would be eligible for marketing to children was calculated with the use of each model, overall and by food category. The Modified-PAHO and PAHO models would permit only 9.8% (95% CI: 9.4%, 10.3%) and 15.8% (95% CI: 15.3%, 16.4%) of foods, respectively, followed by the EURO model [29.8% (95% CI: 29.0%, 30.5%)]. In contrast, the FSANZ-NPSC would consider almost half of prepackaged foods as eligible for marketing to children [49.0% (95% CI: 48.2%, 49.8%)]. Cross-classification analyses showed that only 8.1% of foods would be eligible based on all models (e.g., most pastas without sauce). Subanalyses showed that each model would be more stringent when evaluating food items that specifically target children on their package ( = 747; from 1.9% of foods eligible under Modified-PAHO to 24.2% under FSANZ-NPSC). The degree of strictness and agreement vary greatly between NP models applicable to marketing restrictions. The discrepancies between models highlight the importance for policy makers to carefully evaluate the characteristics underlying such models when trying to identify a suitable model to underpin regulations restricting the marketing of unhealthy foods to children.

Nutrient profiling (NP) is a method for evaluating the healthfulness of foods. Although many NP models exist, most have not been validated. This study aimed to examine the content and construct/convergent validity of five models from different regions: Australia/New Zealand (FSANZ), France (Nutri-Score), Canada (HCST), Europe (EURO) and Americas (PAHO). Using data from the 2013 UofT Food Label Information Program (n15342 foods/beverages), construct/convergent validity was assessed by comparing the classifications of foods determined by each model to a previously validated model, which served as the reference (Ofcom). The parameters assessed included associations (Cochran–Armitage trend test), agreement (κ statistic) and discordant classifications (McNemar’s test). Analyses were conducted across all foods and by food category. On the basis of the nutrients/components considered by each model, all models exhibited moderate content validity. Although positive associations were observed between each model and Ofcom (all P trend<0·001), agreement with Ofcom was ‘near perfect’ for FSANZ (κ=0·89) and Nutri-Score (κ=0·83), ‘moderate’ for EURO (κ=0·54) and ‘fair’ for PAHO (κ=0·28) and HCST (κ=0·26). There were discordant classifications with Ofcom for 5·3 % (FSANZ), 8·3 % (Nutri-Score), 22·0 % (EURO), 33·4 % (PAHO) and 37·0 % (HCST) of foods (all P<0·001). Construct/convergent validity was confirmed between FSANZ and Nutri-Score v. Ofcom, and to a lesser extent between EURO v. Ofcom. Numerous incongruencies with Ofcom were identified for HCST and PAHO, which highlights the importance of examining classifications across food categories, the level at which differences between models become apparent. These results may be informative for regulators seeking to adapt and validate existing models for use in country-specific applications.