The aim of this umbrella review was to summarise the evidence from existing systematic reviews on the association between different dietary patterns (DP) and overweight or obesity outcomes in adults.

We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and searched the MEDLINE, EMBASE, CINAHL, Cochrane, Scopus, and Web of Science for systematic reviews reporting on DP and weight gain or overweight/obesity outcomes.

We identified 16 systematic reviews with 143 unique studies published between 2001 and 2019. Overall quality scores ranged from 4 to 10. Six reviews in 2/11 cohort and 6/19 cross-sectional studies reported (statistically significant) decreased OR for obesity (range: 0·53 to 0·73 and 0·35 to 0·88, respectively) associated with the Mediterranean diet. Five reviews in 5/15 cohort and 10/45 cross-sectional studies reported an inverse association between diet quality and weight gain or BMI (β range: –1·3 to –0·09). Two reviews in 1/3 cohort and 1/2 cross-sectional studies reported a decreased risk of obesity (OR = 0·76) and weight gain (OR = 0·26), respectively, with fruit and vegetable intake. Five reviews of mixed DP in 3/40 cross-sectional studies reported an increased prevalence of obesity (OR = 1·19) or abdominal obesity (OR range: 1·07 to 1·27) with the Korean diet pattern.

Our umbrella review confirms the hypothesis that Mediterranean-type DP reduce the risk of obesity in adults. Although population-specific evidence of effective interventions is needed, characteristics of Mediterranean-type DP are important considerations for national obesity prevention strategies.

To investigate the extent, quality and challenges of dietetic counselling during the pandemic.

A cross-sectional online thirty-six-item Google Survey. The survey queried demographics and information on usage and perceived telemedicine quality.

The survey was distributed to Israeli Dietetic Association (ATID) mailing list between 31 March and 5 May 2020.

Clinical dietitians, members of ATID, who consented to participated in the survey.

Three hundred dietitians (12 % of ATID members; 95 % women; mean age 4·41 (sd 10·2) years) replied to the survey. Most dietitians reported a significant ∼30 % decrease in work hours due to the pandemic. The most prevalent form of alternative nutrition counselling (ANC) was over the phone (72 %); 53·5 % used online platforms. Nearly 45 % had no former ANC experience. Both ANC formats were reported inferior to face-to-face nutritional consultation (consultation quality median scores 8 and 7, on a 1–10 scale, for online and phone, respectively). ANC difficulties on either phone or online platforms were technical (56 and 47 %, respectively), lack of anthropometric measurements (28 and 25 %, respectively) and interpersonal communication (19 and 14·6 %, respectively). Older age and former phone counselling experience were associated with higher quality scores, respectively (OR = 1·046, 95 % CI 1·01, 1·08, P = 0·005), (95 % CI 1·38, 4·52, P = 0·02). Those who continued to work full time had five-time greater odds for a higher quality score using online platforms (OR = 5·33, 95 % CI 1·091, 14·89, P = 0·001).

Our findings suggest telemedicine holds considerable promise for dietary consultation; however, additional tools and training are needed to optimise remote ANC, especially in light of potential crisis-induced lockdown.

Measures of glycaemic impact (e.g. postprandial glucose (PPG), oral glucose tolerance test (OGTT) and glycaemic index (GI)) are used by government health and regulatory agencies and public health associations around the world. The objective of this global review was to identify similarities and differences in the use of glycaemic impact measures for potential considerations for harmonisation.

A literature and internet search was conducted to identify country government agencies and health associations that provide guidance or recommendations for PPG, OGTT, GI and glycaemic load.

Based on this global review, the use of GI for food labelling (e.g. low GI) is limited and its use is voluntary. The application of OGTT as a diagnostic measurement of diabetes and gestational diabetes is widely used and in a consistent manner among the different regions of the world. Time-specific (e.g. 2 h) PPG is commonly used as a target not to exceed in individuals with diabetes and gestational diabetes. PPG is used by regulatory agencies for the substantiation of food labelling. There are differences, however, among regulatory agencies in the specific measure of PPG (i.e. PPG AUC v. peak PPG). Maximum targets for 2-h PPG for individuals with diabetes and gestational diabetes, ranging between 6 and 10 mmol/l, across countries suggest a potential consideration to harmonise PPG targets.

There is general consistency in the use and/or target levels of glycaemic impact measures; however, there is a potential need to investigate harmonisation strategies on certain aspects of glycaemic impact measures.

To evaluate the effect of a sugar-sweetened beverage (SSB) tax implemented in Oakland, California, in July 2017, on prices of beverages sold in fast-food restaurants 2-year post-tax.

Using a difference-in-differences (DID) approach, we analysed beverage price data collected from fast-food restaurants 1-month pre-tax and 2-year post-tax in Oakland (intervention site) and Sacramento, California (comparison site). Separate linear regression models were used to estimate the impact of the tax on prices of bottled regular soda, bottled diet soda, bottled unsweetened beverages and fountain drinks.

Oakland and Sacramento, California, USA.

Chain and non-chain fast-food restaurants (n 85).

DID estimates indicate that in fast-food restaurants, on average, the price of bottled regular soda increased by 1·44 cents/oz (95 % CI 0·50, 2·73) (tax pass-through rate of 144 %) and the price of bottled diet soda increased by 1·17 cents/oz (95 % CI 0·07, 2·13). No statistically significant differences were found between bottled regular and diet soda price increases. Price effects for unsweetened beverages and fountain drinks were not statistically significant. Further, the estimated price change for fountain drinks was nearly zero.

Findings suggest that the effectiveness of SSB taxes in discouraging SSB consumption may be limited in fast-food restaurants in Oakland, California, because there were similar price increases in taxed and untaxed bottled soda and no changes in fountain drink prices.

To estimate the burden of excess weight in Brazilian adolescents.

Systematic review with meta-analysis.

We searched the literature in four databases (MEDLINE/PubMed, EMBASE, SciELO and LILACS). Studies were included if they had cross-sectional or cohort design and enrolled Brazilian adolescents. Studies based on self-reported measures were excluded. Random effect models were used to calculate prevalence estimates and their 95 % CI.

Brazilian adolescents (10 to 19 years old).

One hundred and fifty-one studies were included. Trend analyses showed a significant increase in the prevalence of excess weight in the last decades: 8·2 % (95 % CI 7·7, 8·7) until year 2000, 18·9 (95 % CI 14·7, 23·2) from 2000 to 2009, and 25·1 % (95 % CI 23·4, 26·8) in 2010 and after. A similar temporal pattern was observed in the prevalence of overweight and obesity separately. In sensitivity analyses, lower prevalence of excess weight was found in older adolescents and those defined using International Obesity Task Force cut-off points. The Southeast and South regions had the highest prevalence of excess weight, overweight and obesity. No significant difference in prevalence by sex was found, except for studies before the year 2000.

The prevalence of overweight and obesity in Brazilian adolescents is high and continues to rise. Public policies on an individual level and targeting modifications in the obesogenic environment are necessary.