Estimation of species richness based on species range

A geographical region, containing an unknown number of species, is partitioned into N quadrats. The range of a species is defined to be the number of quadrats in which the species is present. A random sample of n quadrats is drawn without replacement, and the species list is determined for each of the selected quadrats. Two estimators of S are proposed. The inclusion probabilities in the Horvitz-Thompson estimator involve the unknown species ranges but these ranges can be estimated to yield an "estimated" Horvitz-Thompson estimator. This estimator is biased because of the use of estimated inclusion probabilities. For the other estimator, it is shown that the expected number of species in the sample having a specified sample range r is a linear combination over R of the number S R of species in the population with population range R. Letting r vary yields a system of linear equations that can be solved to obtain estimates for the S R and for S. These estimators for SR and S are shown to be unbiased when the sample size n is sufficiently large

Breakfast Dietary Patterns among Mexican Children Are Related to Total-Day Diet Quality

Background: Mexico has experienced shifts in food availability and consumption patterns over the past few decades from traditional diets to those containing more high-energy density foods, resulting in the development of unhealthful dietary patterns among children and adults. However, to our knowledge it is not known whether breakfast consumption patterns contribute to the overall daily diet of Mexican children.Objective: We examined total-day diet among breakfast consumers compared with breakfast skippers, identified and investigated breakfast dietary patterns in relation to energy and nutrient intakes at breakfast and across the day, and examined these patterns in relation to sociodemographic characteristics.Methods: With the use of nationally representative dietary data (one 24-h recall) from the 2012 Mexican National Health and Nutrition Survey, 3760 children aged 4-13 y were categorized into mutually exclusive breakfast patterns with the use of cluster analysis. The association between breakfast patterns and breakfast skippers with dietary intake at breakfast and for the total day was investigated with the use of multivariate linear regression.Results: Most children (83%) consumed breakfast. Six breakfast dietary patterns were identified (milk and sweetened breads, tortillas and beans, sweetened beverages, sandwiches and quesadillas, eggs, and cereal and milk) and reflected both traditional and more Westernized dietary patterns. Sugar-sweetened beverages were consumed across all patterns. Compared with all breakfast dietary patterns, breakfast skippers had the lowest intake of several nutrients of public health concern. Nutrients to limit that were high at breakfast tended to be high for the total day and vice versa for nutrients to encourage.Conclusions: There was not a single pattern that complied perfectly with the Mexican School Breakfast Guidelines, but changes such as increasing dietary fiber by encouraging more whole grains, fruits, vegetables, and beans and reducing sodium and sugar-sweetened beverages could support compliance with these targets and improve overall diet quality

Do high vs. low purchasers respond differently to a nonessential energy-dense food tax? Two-year evaluation of Mexico's 8% nonessential food tax

It is unclear whether response to a nonessential food tax varies across time or for high vs. low-consuming households. The objective is to examine whether the effect of Mexico's 2014 8% nonessential energy-dense foods tax increased in the second year post-implementation and whether it differentially affected households by pre-tax purchasing pattern. We used longitudinal data on Mexican household food purchases (n = 6089 households) from 2012 to 2015. Households were classified based on median pre-tax purchases: low untaxed/low taxed (“low”), low untaxed/high taxed (“unhealthy”), high untaxed/low taxed (“healthy”), and high untaxed/high taxed (“high”) purchasers. Fixed effects models tested whether observed post-tax purchases differed from the counterfactual, or what would have been expected based on pre-tax trends. Post-tax declines in the % taxed food purchases increased from − 4.8% in year one to − 7.4% in year two, yielding a 2-year mean decline of 6.0% beyond the counterfactual (p < 0.01). Post-tax change in % taxed food purchases varied by pre-tax purchasing level. Healthy purchasers showed no post-tax change in % taxed food purchases beyond the counterfactual, while unhealthy, low and high purchasers decreased (− 12.3%, − 5.3% and − 4.4%, respectively) (p < 0.01). The positive effect of Mexico's junk food tax continued in the second year, and households with greater preferences for taxed foods showed a larger decline in taxed food purchases

The widespread presence of non-nutritive sweeteners challenges adherence to beverage guidance for children

Non-nutritive sweeteners (NNS), including aspartame, sucralose, saccharin, acesulfame-K, neotame and advantame are food additives approved for use in foods and beverages by the US Food and Drug Administration (FDA). Two additional NNS, steviol glycosides (often referred to as “stevia”) and monk fruit, are considered to have GRAS (“Generally Recognized as Safe”) status and are permitted for specific conditions of use in the food supply. NNS are a heterogeneous group of compounds with different chemical structures, however they are all potently sweet relative to sugar and contain no or few calories, which makes them popular substitutes for added sugars in foods and beverage

Sugar-sweetened beverage intake among chilean preschoolers and adolescents in 2016: A cross-sectional analysis

Background: Chile has the highest sugar-sweetened beverage (SSB) sales of any country and a growing burden of childhood obesity. This study examines SSB intake in Chilean children after a 5% SSB tax increase in 2014 but prior to marketing, labeling, and school policies implemented in 2016. Methods: 24-h recalls were collected in 2016 from two cohorts comprised of preschoolers 3–5 years of age (n = 961) and adolescents 12–14 years of age (n = 770) from low–moderate income neighborhoods. Beverages were categorized as regulated or unregulated according to whether they exceeded nutrient thresholds established by the 2016 policies. Results: Preschoolers consumed mainly beverage calories from regulated dairy beverages and substitutes (109 kcal, SD 30), unregulated dairy beverages (102 kcal, SD 24), and regulated fruit and vegetables drinks (44 kcal, SD 20). For adolescents, the greatest contributions came from regulated sodas (77 kcal, SD 47), regulated dairy beverages and substitutes (41 kcal, SD 16), and unregulated coffee and tea (41 kcal, SD 11). Overall, regulated beverages provided a greater proportion of calories than unregulated for preschoolers (15.0% vs. 11.8%) and for adolescents (9.1% vs. 5.0%). Conclusions: Before major policy implementation, regulated beverages accounted for a higher percentage of energy intake than unregulated beverages among both age groups. Future research will be needed to evaluate the impact of Chile’s new policies on sugary beverage intake in children

An evaluation of Chile’s law of food labeling and advertising on sugar-sweetened beverage purchases from 2015 to 2017: A before-and-after study

Background Chile’s Law of Food Labeling and Advertising, implemented in 2016, was the first national regulation to jointly mandate front-of-package warning labels, restrict child-directed marketing, and ban sales in schools of all foods and beverages containing added sugars, sodium, or saturated fats that exceed set nutrient or calorie thresholds. The objective of this study is to evaluate the impact of this package of policies on household beverage purchases. Method and findings In this observational study, monthly longitudinal data on packaged beverage purchases were collected from urban-dwelling households (n = 2,383) participating in the Kantar Word-Panel Chile Survey from January 1, 2015, to December 31, 2017. Beverage purchases were linked to nutritional information at the product level, reviewed by a team of nutritionists, and categorized as “high-in” or “not high-in” according to whether they contained high levels of nutrients of concern (i.e., sugars, sodium, saturated fat, or energy) according to Chilean nutrient thresholds and were thus subject to the law’s warning label, marketing restriction, and school sales ban policies. The majority of high-in beverages were categorized as such because of high sugar content. We used fixed-effects models to compare the observed volume as well as calorie and sugar content of postregulation beverage purchases to a counterfactual based on preregulation trends, overall and by household-head educational attainment. Of households included in the study, 37% of household heads had low education (less than high school), 40% had medium education (graduated high school), and 23% had high education (graduated college), with the sample becoming more educated over the study period. Compared to the counterfactual, the volume of high-in beverage purchases decreased 22.8 mL/capita/day, postregulation (95% confidence interval [CI] −22.9 to −22.7; p 0.001), or 23.7% (95% CI −23.8% to −23.7%). High-educated and low-educated households showed similar absolute reductions in high-in beverage purchases (approximately 27 mL/capita/day; p 0.001), but for high-educated households this amounted to a larger relative decline (−28.7%, 95% CI −28.8% to −28.6%) compared to low-educated households (−21.5%, 95% CI −21.6% to −21.4%), likely because of the high-educated households’ lower level of high-in beverage purchases in the preregulation period. Calories from high-in beverage purchases decreased 11.9 kcal/capita/day (95% CI −12.0 to −11.9; p 0.001) or 27.5% (95% CI −27.6% to −27.5%). Calories purchased from beverages classified as “not high-in” increased 5.7 kcal/capita/day (95% CI 5.7–5.7; p 0.001), or 10.8% (10.8%–10.8%). Calories from total beverage purchases decreased 7.4 kcal/capita/day (95% CI −7.4 to −7.3; p 0.001), or 7.5% (95% CI −7.6% to −7.5%). A key limitation of this study is the inability to assess causality because of its observational nature. We also cannot determine whether observed changes in purchases are due to reformulation or consumer behavioral change, nor can we parse out the effects of the labeling, marketing, and school sales ban policies. Conclusions Purchases of high-in beverages significantly declined following implementation of Chile’s Law of Food Labeling and Advertising; these reductions were larger than those observed from single, standalone policies, including sugar-sweetened-beverage taxes previously implemented in Latin America. Future research should evaluate the effects of Chile’s policies on purchases of high-in foods, dietary intake, and long-term purchasing changes

Snacking patterns among Chilean children and adolescents: Is there potential for improvement?

Objective: To examine snacking patterns, food sources and nutrient profiles of snacks in low- and middle-income Chilean children and adolescents. Design: Cross-sectional. Dietary data were collected via 24 h food recalls. We determined the proportion of snackers, snacks per day and energy from top food and beverage groups consumed. We compared the nutrient profile (energy, sodium, total sugars and saturated fat) of snacks v. meals. Setting: South-east region of Chile. Participants: Children and adolescents from two cohorts: the Food Environment Chilean Cohort (n 958, 4-6 years old) and the Growth and Obesity Cohort Study (n 752, 12-14 years old). Results: With a mean of 2·30 (se 0·03) snacks consumed daily, 95·2 % of children and 89·9 % of adolescents reported at least one snacking event. Snacks contributed on average 1506 kJ/d (360 kcal/d) in snacking children and 2218 kJ/d (530 kcal/d) in snacking adolescents (29·0 and 27·4 % daily energy contribution, respectively). Grain-based desserts, salty snacks, other sweets and desserts, dairy foods and cereal-based foods contributed the most energy from snacks in the overall sample. For meals, cereal-based foods, dairy beverages, meat and meat substitutes, oils and fats, and fruits and vegetables were the top energy contributors. Conclusions: Widespread snacking among Chilean youth provides over a quarter of their daily energy and includes foods generally considered high in energy, saturated fat, sodium and/or total sugars. Future research should explore whether snacking behaviours change as the result of Chile's national regulations on food marketing, labelling and school environments

Dietary intake by food source and eating location in low- and middle-income chilean preschool children and adolescents from southeast Santiago

Background: Food source and eating location are important factors associated with the quality of dietary intake. In Chile the main food sources and eating locations of preschool children and adolescents and how these relate to dietary quality are unknown. Methods: We analyzed 24 h dietary recalls collected in 2016 from low- and middle-income Chilean preschool children (3–6 years, n = 839) and adolescents (12–14 years, n = 643) from southeastern Santiago. Surveys collected the food source and eating location for each food reported during the recall. We estimated the mean intake of calories and key nutrients of concern, such as saturated fats, total sugars, and sodium, by food source and eating location. Results: Foods obtained and eaten at home contributed the greatest proportion of total calories and the key nutrients of concern. Foods obtained at home tended to have lower caloric densities but higher sugar and sodium densities than foods obtained away from home in both age groups. With regard to location, for preschool children foods consumed at home had lower caloric and sugar densities than foods eaten at school, while for adolescents foods consumed at home had lower caloric, saturated fat, and sugar densities than foods eaten at school. For both children and adolescents, home was the primary source of sugar-sweetened beverages (SSBs) calories. SSBs were important calorie contributors among foods across all settings, but the highest absolute amount of calories from these beverages was consumed at home. Conclusions: While most of Chilean youths’ calories and key nutrients of concern are obtained and consumed at home, these foods tended to have lower caloric densities than foods obtained and consumed away from home. Home was the main food source for SSBs, but the relative consumption of these beverages was high in all eating locations. More research will be needed to inform and evaluate policies and interventions to improve children’s dietary quality across settings

Changes in food purchases after the Chilean policies on food labelling, marketing, and sales in schools: a before and after study

Background: In 2016, Chile implemented a unique law mandating front-of-package warning labels, restricting marketing, and banning school sales for products high in calories, sodium, sugar, or saturated fat. We aimed to examine changes in the calorie, sugar, sodium, and saturated fat content of food and beverage purchases after the first phase of implementation of this law. Methods: This before and after study used longitudinal data on food and beverage purchases from 2381 Chilean households from Jan 1, 2015, to Dec 31, 2017. Nutrition facts panel data from food and beverage packages were linked to household purchases at the product level using barcode, brand name, and product description. Nutritionists reviewed each product for nutritional accuracy and categorised it as high-in if it contained added sugar, sodium, or saturated fat and exceeded phase 1 nutrient or calorie thresholds, and thus was subject to the labelling, marketing, and school regulations. Using fixed-effects models, we examined the mean nutrient content (overall calories, sugar, saturated fat, and sodium) of purchases in the post-policy period compared to a counterfactual scenario based on pre-policy trends. Findings: Compared with the counterfactual scenario, overall calories purchased declined by 16·4 kcal/capita/day (95% CI –27·3 to –5·6; p=0·0031) or 3·5%. Overall sugar declined by 11·5 kcal/capita/day (–14·6 to –8·4; p<0·0001) or 10·2%, and saturated fat declined by 2·2 kcal/capita/day (–3·8 to –0·5; p=0·0097) or 3·9%. The sodium content of overall purchases declined by 27·7 mg/capita/day (–46·3 to –9·1; p=0·0035) or 4·7%. Declines from high-in purchases drove these results with some offset by increases in not-high-in purchases. Among high-in purchases, relative to the counterfactual scenario, there were notable declines of 23·8% in calories purchased (–49·4 kcal/capita/day, 95% CI –55·1 to –43·7; p<0·0001), 36·7% in sodium purchased (–96·6 mg/capita/day,–105·3 to –87·8; p<0·0001), and 26·7% in sugar purchased (–20·7 kcal/capita/day, –23·4 to –18·1; p<0·0001). Interpretation: The Chilean phase 1 law of food labelling and advertising policies were associated with reduced high-in purchases, leading to declines in purchased nutrients of concern. Greater changes might reasonably be anticipated after the implementation of phases 2 and 3. Funding: Bloomberg Philanthropies, International Development Research Center, and Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health