Consumption of plant foods, including whole grains, vegetables, fruits, pulses, nuts, and seeds, is linked to improved health outcomes. Dietary fiber is a nutrient in plant foods that is associated with improved health outcomes, including a lower risk of chronic diseases such as cardiovascular disease, type 2 diabetes, and certain cancers. Different fibers deliver different health benefits based on their physiochemical properties (solubility, viscosity) and physiological effects (fermentability). Additionally, plant foods contain more than dietary fiber and are rich sources of bioactives, which also provide health benefits. The concept of the solubility of fiber was introduced in the 1970s as a method to explain physiological effects, an idea that is no longer accepted. Dividing total dietary fiber (TDF) into insoluble dietary fiber (IDF) and soluble dietary fiber (SDF) is an analytical distinction, and recent work finds that IDF intake is linked to a wide range of health benefits beyond increased stool weight. We have focused on the IDF content of plant foods and linked the concept of IDF to the bioactives in plant foods. Ancestral humans might have consumed as much as 100 g of dietary fiber daily, which also delivered bioactives that may be more important protective compounds in disease prevention. Isolating fibers to add to human diets may be of limited usefulness unless bioactives are included in the isolated fiber supplement.

Background/objectives: Biological sex factors and sociocultural gender norms affect the physiology and behavior of weight loss. However, most diet intervention studies do not report outcomes by sex, thereby impeding reproducibility. The objectives of this study were to compare 12-month changes in body weight and composition in groups defined by diet and sex, and adherence to a healthy low carbohydrate (HLC) vs. healthy low fat (HLF) diet. Participants/methods: This was a secondary analysis of the DIETFITS trial, in which 609 overweight/obese nondiabetic participants (age, 18–50 years) were randomized to a 12-month HLC (n = 304) or HLF (n = 305) diet. Our first aim concerned comparisons in 12-month changes in weight, fat mass, and lean mass by group with appropriate adjustment for potential confounders. The second aim was to assess whether or not adherence differed by diet-sex group (HLC women n = 179, HLC men n = 125, HLF women n = 167, HLF men n = 138). Results: 12-month changes in weight (p < 0.001) were different by group. HLC produced significantly greater weight loss, as well as greater loss of both fat mass and lean mass, than HLF among men [−2.98 kg (−4.47, −1.50); P < 0.001], but not among women. Men were more adherent to HLC than women (p = 0.02). Weight loss estimates within group remained similar after adjusting for adherence, suggesting adherence was not a mediator. Conclusions: By reporting outcomes by sex significant weight loss differences were identified between HLC and HLF, which were not recognized in the original primary analysis. These findings highlight the need to consider sex in the design, analysis, and reporting of diet trials.

Both vegetable and fruit consumption contribute to wellness and disease prevention. Most dietary health messages promote both together and position the word “fruits” before “vegetables.” We examined the word order of the commonly used phrase “fruits and vegetables” through linguistics, psychology, botany, nutrition, health outcomes, and current US intake to determine if the common word order best presents these two foods in health messaging. By comparing the 10 most commonly consumed vegetables versus fruits, we found that vegetables scored higher on the Aggregate Nutrient Density Index and contained fewer calories and more fiber than fruits. Among the “nutrients of public concern” listed in the 2015 Dietary Guidelines for Americans, we determined that vegetables are better sources of these nutrients than fruits, although fruits scored higher in antioxidant content. In observational cohort studies, vegetable and fruit consumption was found to be associated with decreased mortality. Finally, daily intakes of both vegetables and fruits are lower than recommended, but the discrepancy is larger for vegetables—especially among children—suggesting a greater imperative to promote vegetables. For these reasons, future health messages promoting both together should intentionally put “vegetables” first to promote intake and emphasize their importance regarding contribution to health.

The daily intake of dietary fiber is well below the recommended levels in the US. The effect of adopting a low-fat vs. a low-carbohydrate weight loss diet on fiber intake is of interest but not well-documented, especially when both approaches promote high-quality food choices. The objective of this paper is to compare the quantity and sources of dietary fiber between a healthy low-fat (HLF) vs. healthy low-carbohydrate (HLC) diet group when consumed over 12 months in a weight loss diet study. In this secondary analysis of the Diet Intervention Examining The Factors Interacting with Treatment Success (DIETFITS) study, the amount and sources of dietary fiber were examined in generally healthy adults, 18–50 years of age, Body Mass Index (BMI) 28–40 kg/m², randomized to HLF or HLC for 12 months, who had available 24-h recalls at 0 (n = 609), 3 (n = 549), 6 (n = 491), and 12 (n = 449) months. The dietary intake was estimated by the Nutrition Data System for Research (NDS-R). The sources of fiber were determined for the major food groups. Significantly more total dietary fiber was consumed by HLF at every post-randomization time point, and, at 12 m, was 23.04 ± 9.43 g vs. 18.61 ± 8.12 g for HLF vs. HLC, respectively, p < 0.0001. In both diet groups at 12 months, the highest amount of dietary fiber came from non-starchy vegetables (4.13 ± 3.05 g and 5.13 ± 3.59 g). The other primary sources of fiber at 12 months for the HLF group were from whole grains (3.90 ± 3.13 g) and fruits (3.40 ± 2.87 g), and, for the HLC group, were from plant protein and fat sources, such as nuts and seeds, their butters, and avocados (2.64 ± 2.64 g). In the DIETFITS study, the difference in the total fiber intake for the HLF vs. HLC groups was more modest than expected. The HLC group consumed reasonably high amounts of fiber from high-protein and high fat plant-based sources.

BACKGROUND Most obesity management interventions do not achieve sustained behavior change and, thus, do not result in long term weight loss. A promising approach to weight loss involves mindful eating coaching, which increases awareness of internal cues including hunger and satiety. The purpose of this study was to evaluate the use of a novel technology that promotes mindful eating and drinking behaviors by providing contextual, real-time micro-nudges on wrist-worn wearable devices. OBJECTIVE Evaluate the use of a novel technology, promoting mindful eating and drinking behaviors using contextual micro-nudges on a wrist-worn device, and assess how it facilitates behavior change and weight loss. METHODS Participants used the mindful eating technology for 5 weeks. The primary outcomes of interest collected at the end of the intervention were user acceptability and engagement. Secondary outcomes collected before and at the end of the intervention were mindfulness while eating, consumptions behaviors, and weight loss. RESULTS 17 overweight and obese people completed the intervention. They found the technology to be highly acceptable: 75% reported that using the wearable on their dominant hand felt natural; 88% found it convenient to keep their phone nearby and use the wearable all day; 75% did not find the wearable’s vibrations (haptic) associated with the micro-nudges to be disruptive to the meal experience; 88% enjoyed having the Klue metrics visible on their wearable at all times. On average, the duration of the intervention was 34.2 days (SD 1.2). On average, participants used the app for all but 1.8 (SD 2.0) days, 13.0 (SD 1.0) hours per day when active, received to 27.2 micro-nudges (notifications) per day and engaged in 13.9 daily interactive coaching moments. Moreover, 94% of participants significantly improved their scores on the validated Mindful Eating Questionnaire (P=.001). Similarly, 94% of participants reported improving at least one consumption behavior during the study and 77% reported improving three or more consumption behaviors (e.g., eating more mindfully, remaining well hydrated). Average weight loss was 1.3kg (SD 2.3, P=0.03). CONCLUSIONS The novel technology evaluated in this study provided real-time micro-nudges on a wrist-worn wearable that were acceptable to users and used frequently. Technologies such as these that interact with the user in-the-moment as behaviors are developing may lead to sustained engagement and could have a significant role in increasing mindful eating and producing positive behavior changes associated with successful weight loss. CLINICALTRIAL Stanford e-Protocol #39068