Protein Adequacy, Plant Protein Proportion, and Main Plant Protein Sources Consumed Across Vegan, Vegetarian, Pescovegetarian, and Semivegetarian Diets: A Systematic Review.

BACKGROUND: There are several types of plant-based diets, with unknown differences across diets on total/plant protein intake and variety of plant protein sources consumed. OBJECTIVES: This systematic review aimed to compare total protein intake, proportion of plant proteins, and main plant protein sources consumed across 4 primarily plant-based diets: vegan, vegetarian, pescovegetarian, and semivegetarian. METHODS: We included observational studies reporting on protein intake and/or protein sources in generally healthy adults that were published between 2002 and 2023. We determined the following: 1) % energy from total and plant protein; 2) the proportion of plant protein relative to total protein intake; and 3) main plant protein sources (median percentage contribution of each source to total plant protein intake; interquartile range) consumed across the 4 diets. The plant protein sources were broadly classified into the following United States Department of Agriculture food groups: grains; nuts and seeds; soy products; and beans, peas, and lentils. RESULTS: We included 13 studies reporting on protein intake/sources that were conducted in the United States, Europe, and South Korea. Of these, 7 reported on vegan, 11 on vegetarian, 7 on pescovegetarian, and 7 on semivegetarian diets with total protein intake ranging from 10% to 17.4%. Vegan diets had the highest plant protein proportion (range: 77%-98%) and semivegetarian diets the lowest (range: 37%-83%). Plant protein source contribution was the highest from grains (range: 60%-78%). Nuts and seeds were the most consumed in vegetarian diets (7.9%; 2.9%-10.3%) and least in semivegetarian diets (3.7%; 2%-14.8%). Soy products and beans, peas, and lentils were most consumed in vegan diets (17.3%; 16.3%-19.9, and 19.6%; 14.6%-21.3, respectively) and least in semivegetarian (3.7%; 1.3%-13.9%, and 8.5%; 5.2%-10.2%) diets. CONCLUSIONS: Vegan diets has the highest plant protein proportion and a variety of plant protein sources, while semivegetarian diets has the lowest plant protein proportion and mainly relied on grains as a plant protein source.

Associations between Early Life Nutrient Intakes and Brain Maturation Show Developmental Dynamics from Infancy to Toddlerhood: A Neuroimaging Observation Study.

BACKGROUND: Myelin imaging has increasingly been applied to study the impact of nutrition on brain development in recent years. Although individual dynamics for nutrient intakes and myelin trajectories previously have been investigated across childhood, the longitudinal interaction between both remains unclear in typically developed children. OBJECTIVES: The objective of this work was to explore the developmental dynamics of nutrient-myelin interactions from infancy to early childhood using myelin imaging as a marker for brain maturation. METHODS: Brain neuroimaging (1 scan per child) and dietary nutrient intake data were analyzed for 88 nutrients from 293 children (127 female, 62% White) from a longitudinal cohort study in the United States. A sliding window approach was used to investigate correlations between nutrient intakes and brain myelination over a continuous set of age windows. Image processing techniques (Sobel-filter vertical edge detection) were applied to determine age windows with unique association profiles, providing novel insight into how these relationships change with child age. RESULTS: We identified 3 nutrient-myelin windows covering the age range of 1-5 y: window 1 from 6 to 20 mo with 60% positive nutrient correlations, window 2 from 20 to 30 mo with 20% positive correlations, and window 3 from 30 to 60 mo with 37% positive correlations. The windows are aligned with reported myelin and white matter dynamics that change in the first 5 y from fast and steep (window 1) to continued but slower growth (window 3), with window 2 possibly representing the inflection period. CONCLUSIONS: To our knowledge, this is the first study in typically developing children demonstrating the developmental dynamics between early life nutrient intakes and brain maturation in toddlerhood. The knowledge can be applied for identifying targeted and brain-stage-appropriate nutritional interventions for this critical stage of brain development.

A meta-analysis comparing the effectiveness of alternate day fasting, the 5:2 diet, and time-restricted eating for weight loss.

OBJECTIVE: The objective of this meta-analysis was to compare the effectiveness of different intermittent fasting (IF) regimens on weight loss, in the general population, and compare these to traditional caloric energy restriction (CER). METHODS: Three databases were searched from 2011 to June 2021 for randomized controlled trials (RCTs) that assessed weight loss and IF, including alternate day fasting (ADF), the 5:2 diet, and time-restricted eating (TRE). A random effect network analysis was used to compare the effectiveness between the three regimens. Meta-regression analysis was presented as weighted mean differences of body weight loss. RESULTS: The exploratory random effects network analysis of 24 RCTs (n = 1768) ranked ADF as the most effective, followed by CER and TRE. The meta-analysis showed that IF regimens resulted in similar weight loss to CER (mean difference 0.26 kg, 95% CI: -0.31 to 0.84; p = 0.37). Compliance was generally high (>80%) in trials shorter than 3 months. CONCLUSIONS: The present meta-analysis concludes that IF is comparable to CER and a promising alternative for weight loss. Among the three regimens, ADF showed the highest effectiveness for weight loss, followed by CER and TRE. Further well-powered RCTs with longer durations of intervention are required to draw solid conclusions.

Development and Evaluation of a Diet Quality Index for Preschool-Aged Children in an Asian population: The Growing Up in Singapore Towards Healthy Outcomes cohort.

BACKGROUND: Diet quality indexes are useful tools to measure diet quality because they compare dietary intakes against recommendations. A dietary quality index for Asian preschool-aged children is lacking. OBJECTIVE: The aims of this study were to develop and evaluate a dietary quality index for preschool-aged children (ie, the DQI-5) based on Singapore dietary recommendations and to examine diet quality in a cohort of 5-year-old children. An additional aim was to assess associations between sociodemographic characteristics and DQI-5 scores. DESIGN: A secondary analysis was conducted using dietary intake of children from the Growing Up in Singapore Towards healthy Outcomes mother-offspring cohort assessed in 2015-2016 using a validated food frequency questionnaire. The sociodemographic data were assessed at recruitment between June 2009 and September 2010. The DQI-5 was evaluated using a construct validity approach, whereby nutrition parameters associated with diet quality were studied. PARTICIPANTS AND SETTING: Participants were 767 Singaporean children aged 5 years of Chinese, Malay, or Indian ethnicity. MAIN OUTCOME MEASURES: The main outcome measures were the DQI-5 scores and the sociodemographic characteristics associated with diet quality. STATISTICAL ANALYSES PERFORMED: Kruskal-Wallis tests were used to evaluate differences in adherence to dietary recommendations across DQI-5 tertiles. Linear multiple regression analysis was performed to identify sociodemographic characteristics that were associated with diet quality in the children. RESULTS: The DQI-5 consists of 12 food and nutrient components, with a minimum score of zero and a maximum score of 110 points. The higher scores indicate a healthier diet, the mean ± SD DQI-5 score for the children was 61.6 ± 13.2. DQI-5 components with low scores included whole grains, vegetables, and fatty acid ratio, whereas total rice and alternatives and milk and dairy products components were overconsumed by 18% and 24.4% of children, respectively. Children with higher scores were more likely to meet dietary recommendations and had higher intake of nutrients such as dietary fiber, iron, vitamin A, and beta carotene. Children whose mothers were of Malay ethnicity and whose mothers had low income, an education below university, and shared primary caregiver responsibilities were more likely to have lower DQI-5 scores. CONCLUSIONS: The DQI-5 scores revealed diets to be low for several components and excessive for a few. The DQI-5 developed for preschool-aged children in Singapore had adequate construct validity.