Since December 2019, coronavirus disease 2019 (COVID-19) has been spreading steadily, resulting in overwhelmed health-care systems and numerous deaths worldwide. To counter these outcomes, many countries, including France, put in place strict lockdown measures, requiring the temporary closure of all but essential places and causing an unprecedented disruption of daily life. Our objective was to explore potential changes in dietary intake, physical activity, body weight, and food supply during the COVID-19 lockdown and how these differed according to individual characteristics. The analyses included 37,252 adults from the French web-based NutriNet-Santé cohort who completed lockdown-specific questionnaires in April–May 2020. Nutrition-related changes and their sociodemographic, lifestyle, and health-status correlates were investigated using multivariable logistic regression models. Clusters of participants were defined using an ascending hierarchical classification of change profiles derived from multiple correspondence analyses. During the lockdown, trends of unfavorable changes were observed: decreased physical activity (reported by 53% of the participants), increased sedentary time (reported by 63%), increased snacking, decreased consumption of fresh food (especially fruit and fish), and increased consumption of sweets, cookies, and cakes. Yet, the opposite trends were also observed: increased home cooking (reported by 40%) and increased physical activity (reported by 19%). Additionally, 35% of the participants gained weight (mean weight gain in these individuals, 1.8 kg ± SD 1.3 kg) and 23% lost weight (2 kg ± SD 1.4 kg weight loss). All of these trends displayed associations with various individual characteristics. These results suggest that nutrition-related changes occurred during the lockdown in both unfavorable and favorable directions. The observed unfavorable changes should be considered in the event of a future lockdown, and should also be monitored to prevent an increase in the nutrition-related burden of disease, should these diet/physical activity changes be maintained in the long run. Understanding the favorable changes may help extend them on a broader scale. This trial was registered at clinicaltrials.gov as NCT03335644.

Background: The food industry uses artificial sweeteners in a wide range of foods and beverages as alternatives to added sugars, for which deleterious effects on several chronic diseases are now well established. The safety of these food additives is debated, with conflicting findings regarding their role in the aetiology of various diseases. In particular, their carcinogenicity has been suggested by several experimental studies, but robust epidemiological evidence is lacking. Thus, our objective was to investigate the associations between artificial sweetener intakes (total from all dietary sources, and most frequently consumed ones: aspartame [E951], acesulfame-K [E950], and sucralose [E955]) and cancer risk (overall and by site). Methods and findings: Overall, 102,865 adults from the French population-based cohort NutriNet-Santé (2009–2021) were included (median follow-up time = 7.8 years). Dietary intakes and consumption of sweeteners were obtained by repeated 24-hour dietary records including brand names of industrial products. Associations between sweeteners and cancer incidence were assessed by Cox proportional hazards models, adjusted for age, sex, education, physical activity, smoking, body mass index, height, weight gain during follow-up, diabetes, family history of cancer, number of 24-hour dietary records, and baseline intakes of energy, alcohol, sodium, saturated fatty acids, fibre, sugar, fruit and vegetables, whole-grain foods, and dairy products. Compared to non-consumers, higher consumers of total artificial sweeteners (i.e., above the median exposure in consumers) had higher risk of overall cancer (n = 3,358 cases, hazard ratio [HR] = 1.13 [95% CI 1.03 to 1.25], P-trend = 0.002). In particular, aspartame (HR = 1.15 [95% CI 1.03 to 1.28], P = 0.002) and acesulfame-K (HR = 1.13 [95% CI 1.01 to 1.26], P = 0.007) were associated with increased cancer risk. Higher risks were also observed for breast cancer (n = 979 cases, HR = 1.22 [95% CI 1.01 to 1.48], P = 0.036, for aspartame) and obesity-related cancers (n = 2,023 cases, HR = 1.13 [95% CI 1.00 to 1.28], P = 0.036, for total artificial sweeteners, and HR = 1.15 [95% CI 1.01 to 1.32], P = 0.026, for aspartame). Limitations of this study include potential selection bias, residual confounding, and reverse causality, though sensitivity analyses were performed to address these concerns. Conclusions: In this large cohort study, artificial sweeteners (especially aspartame and acesulfame-K), which are used in many food and beverage brands worldwide, were associated with increased cancer risk. These findings provide important and novel insights for the ongoing re-evaluation of food additive sweeteners by the European Food Safety Authority and other health agencies globally. Trial registration: ClinicalTrials.gov NCT03335644.

Background: There is a growing trend for vegetarian and vegan diets in many Western countries. Epidemiological evidence suggesting that such diets may help in maintaining good health is rising. However, dietary and sociodemographic characteristics of vegetarians and vegans are not well known. The aim of this cross-sectional study was to describe sociodemographic and nutritional characteristics of self-reported, adult vegetarians and vegans, compared to meat-eaters, from the French NutriNet-Santé study. Methods: Participants were asked if they were following a specific diet. They were then classified into three self-reported diet groups: 90,664 meat-eaters, 2370 vegetarians, and 789 vegans. Dietary data were collected using three repeated 24-h dietary records. Multivariable polytomic logistic regression models were perfomed to assess the association between the sociodemographic characteristics and type of diet. The prevalence of nutrient intake inadequacy was estimated, by sex and age for micronutrients, as well as by type of self-reported diet. Results: Compared with meat-eaters, vegetarians were more likely to have a higher educational level, whereas vegans had a lower education level. Compared with meat-eaters, vegetarians were more likely to be women, younger individuals, and to be self-employed or never employed rather than managerial staff. Vegetarians and vegans substituted animal protein-dense products with a higher consumption of plant protein-dense products (e.g., soy-based products or legumes). Vegetarians had the most balanced diets in terms of macronutrients, but also had a better adherence to French dietary guidelines. Vegetarians exhibited a lower estimated prevalence of inadequacies for micronutrients such as antioxidant vitamins (e.g., for vitamin E, 28.9% for vegetarian women <55 years of age vs. 41.6% in meat-eaters) while vegans exhibited a higher estimated prevalence of inadequacies for some nutrients, in particular vitamin B12 (69.9% in men and 83.4% in women <55 years of age), compared to meat-eaters. Conclusions: Our study highlighted that, overall, self-reported vegetarians and vegans may meet nutritional recommendations.

Ultra-processed food (UPF) consumption has increased drastically worldwide and already represents 50%–60% of total daily energy intake in several high-income countries. In the meantime, the prevalence of overweight and obesity has risen continuously during the last century. The objective of this study was to investigate the associations between UPF consumption and the risk of overweight and obesity, as well as change in body mass index (BMI), in a large French cohort. A total of 110,260 adult participants (≥18 years old, mean baseline age = 43.1 [SD 14.6] years; 78.2% women) from the French prospective population-based NutriNet-Santé cohort (2009–2019) were included. Dietary intakes were collected at baseline using repeated and validated 24-hour dietary records linked to a food composition database that included >3,500 different food items, each categorized according to their degree of processing by the NOVA classification. Associations between the proportion of UPF in the diet and BMI change during follow-up were assessed using linear mixed models. Associations with risk of overweight and obesity were assessed using Cox proportional hazard models. After adjusting for age, sex, educational level, marital status, physical activity, smoking status, alcohol intake, number of 24-hour dietary records, and energy intake, we observed a positive association between UPF intake and gain in BMI (β Time × UPF = 0.02 for an absolute increment of 10 in the percentage of UPF in the diet, P < 0.001). UPF intake was associated with a higher risk of overweight (n = 7,063 overweight participants; hazard ratio (HR) for an absolute increase of 10% of UPFs in the diet = 1.11, 95% CI: 1.08–1.14; P < 0.001) and obesity (n = 3,066 incident obese participants; HR_10% = 1.09 (1.05–1.13); P < 0.001). These results remained statistically significant after adjustment for the nutritional quality of the diet and energy intake. Study limitations include possible selection bias, potential residual confounding due to the observational design, and a possible item misclassification according to the level of processing. Nonetheless, robustness was tested and verified using a large panel of sensitivity analyses. In this large observational prospective study, higher consumption of UPF was associated with gain in BMI and higher risks of overweight and obesity. Public health authorities in several countries recently started to recommend privileging unprocessed/minimally processed foods and limiting UPF consumption. ClinicalTrials.gov NCT03335644 (https://clinicaltrials.gov/ct2/show/NCT03335644)

Objective: Concerns have been raised about the potential health impact of ultra-processed foods (UPF) in the diet. Our objective was to investigate the contribution of UPF in the diet in a large French population and its association with sociodemographic factors and dietary patterns.Design: Cross-sectional analysis of dietary data from 74 470 participants in the web-based NutriNet-Santé cohort. UPF were identified in repeated 24 h records and the proportion (in weight) of UPF in the total diet (UPFp) was computed for each participant. Associations of sociodemographic characteristics and UPFp in quartiles were assessed using multivariate multinomial logistic regression. Food group consumption and nutrient intakes across quartiles of UPFp were estimated using linear regression adjusted for sociodemographic factors and energy intake.Setting: France.Results: UPF contributed 18·4 % of the foods consumed in weight and 35·9 % of total energy intake. Higher UPFp consumption was independently associated with male gender, younger age, lower education, smoking, and overweight and obesity (all P<0·0001). Participants in the highest UPFp quartile consumed lower amounts of fruit and vegetables (difference between quartile 4 and quartile 1 of UPFp, Δ=−180·3 g/d) and higher amounts of sweet products (Δ=68·5 g/d) and soft drinks (Δ=98·6 g/d; all P<0·0001). They had higher intakes of energy (Δ=610 kJ/d (145·7 kcal/d)) and added sugar (Δ=17·1 g/d), and lower intakes of fibre (Δ=−4·04 g/d), β-carotene (Δ=−1019·6 μg/d) and Ca (Δ=−87·8 mg/d; all P<0·0001).Conclusions: UPF represent an important part of the diet in adults from the French general population and are associated with unbalanced nutritional intakes.

There is a growing availability of industrial plant-based meat and dairy substitutes that can be classified as ultra-processed foods (UPFs). Very little is known about the consumption of UPFs by vegetarians. The aim of this cross-sectional study, from the NutriNet-Santé cohort, was to describe the contribution of UPFs to different vegetarian diets, in relation to the nutritional quality of their diet, and determinants of UPF consumption, including duration and age at vegetarian diet initiation. The study population (n = 21,212) was divided into 4 groups: 19,812 meat eaters, 646 pesco-vegetarians, 500 vegetarians, and 254 vegans. Daily food intakes were collected using repeated 24-h dietary records. Vegetarian diets were described by the proportion of energy from UPFs and the nutritional quality of the diet using healthy and unhealthy plant-based diet indices (PDIs). In a subsample without meat eaters (n = 1,400), a multivariable linear regression model was performed to study the association between UPF consumption and its determinants. Higher avoidance of animal-based foods was associated with a higher consumption of UPFs (P < 0.001), with UPFs supplying 33.0%, 32.5%, 37.0%, and 39.5% of energy intakes for meat eaters, pesco-vegetarians, vegetarians, and vegans. The nutritional quality of diets was also associated with the level of animal-based foods avoidance (P < 0.001), with healthy PDIs at 53.5, 60.6, 61.3 and 67.9 for meat-eaters, pesco-vegetarians, vegetarians, and vegans. Short duration and young age at diet initiation were associated with an increased consumption of UPFs (βage at initiation = -0.003, P = 0.001; βduration = -0.002, P < 0.001). Not all vegetarian diets necessarily have health benefits, because of potential adverse effects of UPFs on nutritional quality and healthiness of diet. UPF consumption by vegetarians and their diet characteristics should be considered in future studies on the links between vegetarianism and health. This trial was registered at clinicaltrials.gov as NCT03335644.