To investigate the association between plant-based diets (PBD) and overweight/obesity compared to regular meat eaters in older women.

Cross-sectional analysis.

1946–1951 birth cohort of the Australian Longitudinal Study on Women’s Health (ALSWH). PBD were categorised as vegan, lacto-ovo vegetarian, pesco-vegetarian, semi-vegetarian and regular meat eaters. Outcomes included body weight (BW), BMI and waist circumference (WC).

Women who completed Survey 7 (n 9102) with complete FFQ data.

Compared to regular meat eaters, BW, BMI and WC were significantly lower in pesco-vegetarians (−10·2 kg (95 % CI −5·1, −15·2); −3·8 kg/m2 (95 % CI −2·0, −5·6); −8·4 cm (95 % CI −3·9, −12·9)) and BW and BMI lower in lacto-ovo vegetarians (−7·4 kg (95 % CI −1·2, −13·6); −2·9 kg/m2 (95 % CI −0·6, −5·1)). In regular meat eaters, individuals consuming meat daily or multiple times/d had significantly higher BW, BMI and WC compared to those consuming meat >2 times/week but <daily or multiple times/d (2·5 kg (95 % CI 1·5, 3·5); 0·9 kg/m2 (95 % CI 0·5, 1·3) and 2·2 cm (95 % CI 1·3, 3·1)) and those consuming meat >1 but ≤2 times/week (6·8 kg (95 % CI 1·8, 11·8); 2·1 kg/m2 (95 % CI 0·3, 4·0) and 6·0 cm (95 % CI 1·7, 10·4)). This association was dose-dependent such that for every increase in category of weekly meat intake (i.e. >1 time/week but ≤2 times/week; >2 times/week but less than daily, and daily or multiple times/d), an associated 2·6 kg (95 % CI 1·8, 3·4) increase in BW, 0·9 kg/m2 (95 % CI 0·6, 1·2) increase in BMI and 2·3 cm (95 % CI 1·6, 3·0) increase in WC was reported.

BW, BMI and WC are lower in women following PBD and positively associated with increasing meat consumption. Results were robust to adjustment for confounders including physical activity levels, smoking status, habitual alcohol intake, use of supplements, and hormone replacement therapy.

To explore adherence to a plant-based diet from the perspective of goals- and motivations-based systems.

A cross-sectional, survey-based study was conducted regarding eating patterns, goals and motivations for current eating habits.

Data were collected using an online survey platform, including the Goal Systems Assessment Battery (GSAB) and other survey tools.

University students were recruited, including thirty-three students reporting successful maintenance of a plant-based diet (Adherents) and sixty-three students trying to adhere to a plant-based diet (Non-adherents).

Using GSAB subscale scores, discriminant function analyses significantly differentiated adherents v. non-adherents, accounting for 49·0 % of between-group variance (χ2 (13) = 42·03, P < 0·000). It correctly classified 72·7 % of adherents and 88·9 % of non-adherents. Constructs including value, self-efficacy, planning/stimulus control and positive affect were significant and included in the discriminant function. Logistic regression results suggested that participants who successfully adhered to a plant-based diet were seventeen times more likely to report ‘To manage or treat a medical condition’ as motivation and almost seven times more likely to report ‘To align with my ethical beliefs’ as motivation compared with non-adherents. However, these participants were 94 % less likely to report ‘To maintain and/or improve my health’ as motivation compared with non-adherents. Controlling for motivations, hierarchical logistic regression showed that only planning as part of the GSAB self-regulatory system predicted adherence to a plant-based diet.

Values-based approaches to plant-based diets, including consideration for ethical beliefs, self-efficacy and proper planning, may be key for successful maintenance of this diet long-term.

To evaluate diets in terms of nutritional characteristics and quality from the perspectives of health, greenhouse gas emissions (GHGE) and possible associations with each other in a representative sample of students at a public university.

Cross-sectional. Dietary intake was evaluated with a validated FFQ, and diet quality was assessed through the Healthy Eating Index (HEI-2010) and MedDietScore (MDS). GHGE data were obtained from the literature. In addition, sex, socio-economic status (SES) and body fat (BF) status were analysed as covariates.

Basque Autonomous Community, Spain.

Totally, 26 165 healthy adults aged 18–28 years.

Student diets were characterised by low consumption of carbohydrates (38·72 % of total energy intake (TEI)) and a high intake of lipids (39·08 % of TEI). Over half of the participants had low dietary quality. The low-emitting diets were more likely to be consumed by subjects with low HEI-2010 scores (β: 0·039 kg eCO2/1000 kcal/d) and high MDS scores (β: −0·023 kg eCO2/1000 kcal/d), after controlling for sex, SES and BF status. Both the low-emitting and healthy diets were more likely to be consumed by women and by those with normal BF percentage.

UPV/EHU university students’ diets were characterised by moderate quality from a nutritional perspective and moderate variation in the size of carbon footprints. In this population, diets of the highest quality were not always those with the lowest diet-related GHGE; this relationship depended in part on the constructs and scoring criteria of diet quality indices used.

To examine the association between adherence to plant-based diets and mortality.

Prospective study. We calculated a plant-based diet index (PDI) by assigning positive scores to plant foods and reverse scores to animal foods. We also created a healthful PDI (hPDI) and an unhealthful PDI (uPDI) by further separating the healthy plant foods from less-healthy plant foods.

The VA Million Veteran Program.

315 919 men and women aged 19–104 years who completed a FFQ at the baseline.

We documented 31 136 deaths during the follow-up. A higher PDI was significantly associated with lower total mortality (hazard ratio (HR) comparing extreme deciles = 0·75, 95 % CI: 0·71, 0·79, Ptrend < 0·001]. We observed an inverse association between hPDI and total mortality (HR comparing extreme deciles = 0·64, 95 % CI: 0·61, 0·68, Ptrend < 0·001), whereas uPDI was positively associated with total mortality (HR comparing extreme deciles = 1·41, 95 % CI: 1·33, 1·49, Ptrend < 0·001). Similar significant associations of PDI, hPDI and uPDI were also observed for CVD and cancer mortality. The associations between the PDI and total mortality were consistent among African and European American participants, and participants free from CVD and cancer and those who were diagnosed with major chronic disease at baseline.

A greater adherence to a plant-based diet was associated with substantially lower total mortality in this large population of veterans. These findings support recommending plant-rich dietary patterns for the prevention of major chronic diseases.

While plant-based dietary practices (PBDPs) have been recommended to improve both population health and environmental sustainability outcomes, no nationally representative Canadian studies have described the prevalence or correlates of excluding animal source foods. The current study therefore: (1) created operationalised definitions of PBDPs based on animal source food exclusions to estimate the prevalence of Canadians who adhere to PBDPs and (2) examined key correlates of PBDPs.

Population representative, cross-sectional data were from the 2015 Canadian Community Health Survey–Nutrition. Respondents’ PBDPs were categorised as: (1) vegan (excluded red meat, poultry, fish, eggs and dairy); (2) vegetarian (excluded red meat, poultry and fish); (3) pescatarian (excluded red meat and poultry) and (4) red meat excluder (excluded red meat). Descriptive statistics and multivariable regression analyses were used to examine the prevalence and correlates of these PBDP categories.

All ten provinces in Canada.

Canadians aged 2 years and above (n 20 477).

In 2015, approximately 5 % of Canadians reported adhering to any PBDP (all categories combined) with the majority (2·8 %) categorised as a red meat excluder, 1·3 % as vegetarian, 0·7 % as pescatarian and 0·3 % as vegan. South Asian cultural identity (OR 19·70 (95 % CI 9·53, 40·69)) and higher educational attainment (OR 1·97 (95 % CI 1·02, 3·80)) were significantly associated with reporting a vegetarian/vegan PBDP.

Despite growing public discourse around PBDPs, only 5 % of Canadians reported PBDPs in 2015. Understanding the social and cultural factors that influence PBDPs is valuable for informing future strategies to promote environmentally sustainable dietary practices.

To identify wild plants used as food and assess their frequency of consumption over a year in a region of Tunisia where agriculture is undergoing a major transformation from smallholder farming to an intensive high-input agricultural system.

Qualitative ethnobotanical study followed by a survey of women’s frequency of consumption of wild plants conducted using FFQ at quarterly intervals.

Sidi Bouzid governorate of central Tunisia.

Mixed-gender group of key informants (n 14) and focus group participants (n 43). Survey sample of women aged 20–49 years, representative at governorate level (n 584).

Ethnobotanical study: thirty folk species of wild edible plants corresponding to thirty-five taxa were identified by key informants, while twenty folk species (twenty-five taxa) were described by focus groups as commonly eaten. Population-based survey: 98 % of women had consumed a wild plant over the year, with a median frequency of 2 d/month. Wild and semi-domesticated fennel (Foeniculum vulgare Mill. and Anethum graveolens) was the most frequently consumed folk species. Women in the upper tertile of wild plant consumption frequency were more likely to be in their 30s, to live in an urban area, to have non-monetary access to foods from their extended family and to belong to wealthier households.

In this population, wild edible plants, predominantly leafy vegetables, are appreciated but consumed infrequently. Their favourable perception, however, offers an opportunity for promoting their consumption which could play a role in providing healthy diets and mitigating the obesity epidemic that is affecting the Tunisian population.

Describe how dietary intake patterns of US young adults align with the EAT-Lancet Planetary Health Diet (PHD) sustainable diet goals and identify personal, behavioural, and socio-environmental correlates of sustainable intake.

Data on past-year dietary intake were captured using a FFQ. The PHD was applied to specific food groups, and a total PHD score was calculated. Linear regression models were used to identify associations between personal, behavioural and socio-environmental factors and PHD scores.

This cross-sectional analysis uses data from the second wave of EAT 2010–2018 (Eating and Activity over Time), a population-based longitudinal study recruited in Minnesota.

Ethnically/racially diverse group of participants (n 1308) with a mean age of 22·1 (sd 2·0) years.

The mean PHD score was 4·1 (sd 1·4) on a scale of 0–14, with 14 representing the most sustainable. On average, participants consumed fewer whole grains, fish, legumes, soya, and nuts than ideal for a sustainable diet, and an excess of eggs, added sugar, and meat. The PHD score was higher for participants with higher socio-economic status (SES) and greater educational attainment. Higher home availability of healthy food (β = 0·24, P < 0·001) and less frequent fast-food consumption (β = –0·26, P < 0·001) were the strongest correlates of PHD scores.

Results suggest that a high percentage of participants may not be achieving the sustainable diet goals defined by the PHD. Reductions in meat consumption and increases in plant-based foods are necessary to increase the sustainability of US young adults’ diets.

Vegetarian diets may be associated with low prevalence of autoimmune disease, as observed in rural sub-Saharan Africans. Graves’ disease, an autoimmune disorder, is the most common cause of hyperthyroidism. We studied prevalence of hyperthyroidism according to dietary pattern in a population with a high proportion of vegetarians.

Cross-sectional prevalence study. The association between diet and prevalence of hyperthyroidism was examined using multivariate logistic regression analyses controlling for sociodemographic characteristics and salt use.

The Adventist Health Study-2 conducted in the USA and Canada.

Church members (n 65 981) provided demographic, dietary, lifestyle and medical history data by questionnaire.

The prevalence of self-reported hyperthyroidism was 0·9 %. Male gender (OR=0·32; 95 % CI 0·26, 0·41) and moderate or high income (OR=0·67; 95 % CI 0·52, 0·88 and OR=0·73; 95 % CI 0·58, 0·91, respectively) protected against hyperthyroidism, while obesity and prevalent CVD were associated with increased risk (OR=1·25; 95 % CI 1·02, 1·54 and OR=1·92; 95 % CI 1·53, 2·42, respectively). Vegan, lacto-ovo and pesco vegetarian diets were associated with lower risk compared with omnivorous diets (OR=0·49; 95 % CI 0·33, OR=0·72, 0·65; 95 % CI 0·53, 0·81 and OR=0·74; 95 % CI 0·56, 1·00, respectively).

Exclusion of all animal foods was associated with half the prevalence of hyperthyroidism compared with omnivorous diets. Lacto-ovo and pesco vegetarian diets were associated with intermediate protection. Further study of potential mechanisms is warranted.

Children from low-income countries consuming predominantly plant-based diets but little animal products are considered to be at risk of Fe deficiency. The present study determined the Fe status of children from resource-limited rural households.

A cross-sectional study.

Twenty six kebeles (the smallest administrative unit) from six zones of the Amhara region, Ethiopia.

Children aged 54–60 months (n 628).

Grain, roots or tubers were the main dietary components consumed by 100 % of the study participants, followed by pulses, legumes or nuts (66·6 %). Consumption of fruit and vegetables (19·3 %) and meat, poultry and fish (2·2 %) was low. Children had a mean dietary diversity score of 2·1 (sd 0·8). Most children (74·8 %, n 470) were in the lowest dietary diversity group (1–2 food groups). Rate of any morbidity in the preceding 14 d was 22·9 % (n 114). Infection or inflammation (α1-acid glycoprotein >1·2 g/l) was present in 30·2 % (n 184) of children. Children had a high rate of stunting (43·2 %). Of the total sample, 13·6 % (n 82) of children were anaemic, 9·1 % (n 57) were Fe deficient and 5·3 % (n 32) had Fe-deficiency anaemia. Fe-deficiency erythropoiesis was present in 14·2 % (n 60) of children.

Despite consuming a predominantly plant-based diet and little animal-source foods, there was a low prevalence of Fe-deficiency anaemia. This illustrates that dietary patterns can be inharmonious with Fe biochemical status; thus, Fe-related interventions require biochemical screening.

The aim of the present study was to investigate the differences between the consumption of plant-based v. animal-based protein-rich diets on successful ageing, as well as to identify the optimal combination of dietary protein intake for facilitating successful ageing in people aged >50 years.

A combined analysis was conducted in older adults of the ATTICA and MEDIS population-based cross-sectional studies. Anthropometrical, clinical and sociodemographic characteristics, lifestyle parameters, dietary habits and level of protein intake were derived through standard procedures. Successful ageing was evaluated using the validated Successful Aging Index (SAI) composed of ten health-related social, lifestyle and clinical characteristics.

Athens area and twenty Greek islands.

A total of 3349 Greek women and men over 50 years old.

Participants with high consumption of plant proteins were more likely to be male, physically active, with higher daily energy intake, higher adherence to the Mediterranean diet and higher level of SAI (P < 0·001). Participants with ‘Low animal & High plant’ and ‘High animal & High plant’ protein consumption had a 6 and 7 % higher SAI score, respectively, compared with the other participants (P < 0·001). In contrast, ‘Low animal & Low plant’ and ‘High animal & Low plant’ protein intake was negatively associated with SAI as compared to the combination of all other consumption categories (P < 0·02).

The consumption of a plant-based protein-rich diet seems to be a beneficial nutritional choice that should be promoted and encouraged to older people since it may benefit both individual’s health and prolong successful ageing.

Are diets with a greater environmental impact less healthy? This is a key question for nutrition policy, but previous research does not provide a clear answer. To address this, our objective here was to test whether American diets with the highest carbon footprints predicted greater population-level mortality from diet-related chronic disease than those with the lowest.

Baseline dietary recall data were combined with a database of greenhouse gases emitted in the production of foods to estimate a carbon footprint for each diet. Diets were ranked on their carbon footprints and those in the highest and lowest quintiles were studied here. Preventable Risk Integrated Model (PRIME), an epidemiological modelling software, was used to assess CVD and cancer mortality for a simulated dietary change from the highest to the lowest impact diets. The diet–mortality relationships used by PRIME came from published meta-analyses of randomised controlled trials and prospective cohort studies.

USA.

Baseline diets came from adults (n 12 865) in the nationally representative 2005–2010 National Health and Nutrition Examination Survey.

A simulated change at the population level from the highest to the lowest carbon footprint diets resulted in 23 739 (95 % CI 20 349, 27 065) fewer annual deaths from CVD and cancer. This represents a 1·83 % (95 % CI 1·57 %, 2·08 %) decrease in total deaths. About 95 % of deaths averted were from CVD.

Diets with the highest carbon footprints were associated with a greater risk of mortality than the lowest, suggesting that dietary guidance could incorporate sustainability information to reinforce health messaging.

To describe continuity over time in reports of valuing sustainable diet practices and investigate relationships between values, household meal behaviours and dietary intake.

Observational study. Participant ratings of how important it is for food to be produced as organic, not processed, locally grown and not GM were categorized to represent whether they valued (very/somewhat important) or did not value (a little/not at all important) each practice. Diet quality markers (e.g. fruit servings) were based on an FFQ.

Mailed and online surveys.

Young adults (n 1620; 58 % female, mean age 31 (sd 1·6) years) who were participating in Project EAT (Eating and Activity among Teens and Young Adults) and responded to follow-up surveys in 2003–2004 and 2015–2016.

One-third (36·1 %) of participants reported valuing <2 practices at both assessments; 11·1 and 34·5 % respectively reported valuing ≥2 practices in 2003–2004 only and in 2015–2016 only; 18·3 % reported valuing ≥2 practices at both assessments. Regression models including demographics, parental status and vegetarian status showed that valuing ≥2 practices was associated with preparation of meals with vegetables at least a few times/week, less frequent purchase of family meals from fast-food restaurants, and higher diet quality in 2015–2016. For example, those who valued ≥2 practices consumed nearly one full vegetable serving more than other young adults on an average day and part of this difference was specifically associated with intake of dark green and red/orange vegetables.

Addressing the sustainability of food choices as part of public health messaging may be relevant for many young adults.

There is an urgent need to identify and develop cross-sectoral policies which promote and support a healthy, safe and sustainable food system. To help shape the political agenda, a critical first step is a shared definition of such a system among policy makers across relevant sectors. The aim of the present study was to determine how Australian policy actors define, and contribute to, a healthy, safe and sustainable food system.

A Delphi survey, consisting of two rounds, was conducted. Participants were asked how they define, and contribute to, a healthy, safe and sustainable food system (Round 1) and indicate their level of agreement with summary statements (Round 2).

This was an online Delphi survey conducted in Australia.

Twenty-nine and fourteen multisectoral and multilevel policy makers completed Round 1 and Round 2, respectively.

The definition included food processing regulation, environmentally friendly food production and access to nutritious food. All agreed that it was important for them to improve access and supply of healthy food and ensure healthy planning principles are applied.

There were cross-sectoral differences in definitions and contributions; however, critical consensus was achieved. The study contributes to the definition of key elements of a cross-sectoral food and nutrition policy to meet today’s environmental, health, social and economic challenges; however, further research using a more representative multisectoral sample is warranted.

To define a generic diet to protect human health and food system sustainability based on three dimensions: animal:plant ratio, degree of food processing and food diversity.

The percentages of maximum animal and ultra-processed energy content were evaluated from scientific papers (Web of Science database) and reports from international scientific institutions. Then, a weekly French standard diet, including these percentages and food diversity (≥42 different foods), was designed to calculate adequacy to nutritional needs.

Based on traditional and scientifically based healthy diets, and on foresight scenarios for sustainable diets at horizon 2050, a median daily animal energy content intake of 15 % was found to be protective towards both human health and environment. Based on epidemiological studies associating ultra-processed energy consumption with increased overweight/obesity risk, a precautionary threshold of approximately 15 % ultra-processed energy content was observed. The French diet allows addressing all nutritional needs and other nutritional indicators such as maximum salt and simple sugar consumption, α-linolenic acid:linoleic acid ratio and essential amino acids. This diet was named the ‘3V rule’ for Végétal (plant), Vrai (real) and Varié (varied, if possible organic, local and seasonal). This generic diet can be adapted according to regional traditions and environmental characteristics. Excluding only one dimension of it would threaten both health and food system sustainability.

Tending towards a 3V-based diet, while respecting local constraints, should allow preserving human health, environment (greenhouse gas emissions, pollution, deforestation, etc.), small farmers, animal welfare and biodiversity, culinary traditions and socioeconomics (including an alleviation of public health cost).

This study examines secular changes in diet-related greenhouse gas emissions (GHGE) in younger and older Swedish adults, since the turn of this century.

Two cross-sectional health examination surveys were conducted in 2001–2004 (T1) and 2014–2018 (T2). At both times, an eighty-six-item FFQ was embedded in the survey. From the food frequencies and age-standardised portion sizes, GHGE estimates (kg CO2e/year) were calculated. GHGE was modelled as a function of time period and covariates, for five distinct age groups.

The municipality of Gothenburg, in western Sweden.

Women and men aged 25–34, 35–44, 45–54, 55–64 and 65–75 years were randomly selected from the population registry and recruited for examinations. After exclusion of participants with incomplete dietary data, the analytic sample consisted of 2569 individuals at T1 and 2119 at T2.

Lower dietary GHGE scores were observed at T2 compared with T1, in each age group, adjusting for sex, BMI and education. The largest differences in GHGE were observed in the youngest age group (approximately 30 % reduction). Decreasing trends in GHGE from animal-based foods were observed at all ages and were accompanied by smaller increases from plant-based sources in younger groups only. At all ages, GHGE from discretionary foods decreased, and prevalence of overweight remained stable.

Optimal dietary trends should support both human health and planetary health. Our results suggest that Swedish adults have moved in this direction, e.g. through less intake of red meat products and stable weight status.

This study aimed to explore barriers and facilitators of the provision of dairy and plant-based dairy alternatives (PBDA) by parents of preschool-age children, a previously unexplored area of research.

Five focus groups of parents were conducted and audio-recorded. Verbatim transcripts were analysed using thematic analysis.

University of Guelph, in Guelph, ON, Canada in 2019.

Thirty-two (n 19 mothers, 13 fathers) parents of preschool-age children. Most (59 %) were university or college educated.

Facilitators common to both dairy and PBDA provision included perceived nutritional benefits, such as dairy’s Ca, protein and fat content, and PBDA’s protein content, and the perception that PBDA adds variety to the diet. Facilitators unique to dairy v. PBDA provision included the taste of, familiarity with, and greater variety and accessibility of dairy products, specifically child-friendly products. A facilitator unique to PBDA v. dairy provision was ethical concerns regarding dairy farming practices. Barriers common to both dairy and PBDA provision included perceived cost, concerns regarding the environmental impact of production, and high sugar content. Barriers specific to dairy included use of antibiotics and hormones in dairy production. A barrier specific to PBDA was the use of pesticides.

Behaviour change messages targeting parents of preschoolers can emphasise the nutrition non-equivalence of dairy and some PBDA and can educate parents on sources of affordable, unsweetened dairy and PBDA.