Time-Restricted Eating Alters Food Intake Patterns, as Prospectively Documented by a Smartphone Application

Effects of 8-h time-restricted eating on energy intake, dietary composition and quality in adolescents with obesity

BACKGROUND

The precise mechanisms underlying the health benefits of time-restricted eating (TRE) are unclear, particularly in adolescents.

OBJECTIVES

This secondary analysis examines the impact of 8-h TRE on energy intake, dietary composition and quality in adolescents with obesity, using data from a 12-week randomized, controlled pilot trial.

METHODS

Participants (14-18 years with BMI >95th percentile) were assigned to either 8-h TRE with real-time or blinded continuous glucose monitoring or a control group with a 12+ h eating window. Dietary intake was analysed using the Nutrient Data System Recall 24-h Dietary Recall and the Healthy Eating Index (HEI-2020) for assessing diet quality.

RESULTS

The study included 44 participants (32 TRE, 12 control), predominantly female and Hispanic/Latino. The TRE group showed a significant reduction in mean energy intake (-441 kcal/day), carbohydrates (-65 g/day), added sugar (-19 g/day) and fat (-19 g/day), while the control group had a similar reduction in energy intake (-437 kcal/day) and carbohydrates (-63 g/day), but no significant changes in added sugar or fat. The percent energy intake from protein increased more in the TRE group compared to the control. The TRE group experienced a significant improvement in diet quality, with a 6.3-point increase in HEI-2020 score; however, between-group comparisons were not statistically significant.

CONCLUSION

There were no significant differences between the TRE and control groups in energy intake, dietary composition or quality. Future research with larger sample sizes is needed to further evaluate the potential impact of TRE on dietary behaviours.

Precision medicine in endocrinology: Unraveling metabolic health through time-restricted eating

As a promising avenue in nutrition, intermittent fasting, particularly time-restricted eating like the 8/16 protocol, requires careful individualization. This approach involves voluntary food restriction interspersed with normal eating, aiming to align with inner circadian rhythms for potential benefits in metabolism and weight management. Endocrinologists, responding to patient interest and backed by evidence-based medicine, can now delve into the intricacies of time-restricted eating. They consider each patient's unique medical history and expectations, integrating this approach into tailored treatment plans in a personalized medicine approach. Ongoing research is essential to deepen our comprehension of how time-restricted eating influences metabolic health, enabling the development of precise recommendations suitable for diverse populations and various clinical conditions. While time-restricted eating is a relevant metabolic approach, endocrinologists should exercise caution to prevent the promotion of eating disorders due to its restrictive nature.

Randomized controlled feasibility trial of late eight-hour time restricted eating for adolescents with type 2 diabetes

BACKGROUND

No trial to date has tested the effects of late time-restricted eating (lTRE) on glycemic control or body composition in adolescents with type 2 diabetes (T2D).

OBJECTIVE

The objective of the current study was to examine the feasibility, acceptability, and preliminary efficacy of lTRE compared to a prolonged eating window in adolescents with T2D.

DESIGN

A 12-week, randomized, controlled, feasibility study of lTRE compared to control in adolescents with obesity and new onset T2D was conducted.

PARTICIPANTS/SETTING

Eligible participants were 13-21 years old; with a diagnosis of T2D, on metformin monotherapy, recruited from Children's Hospital Los Angeles, between January 2021 and December of 2022. From 36 eligible participants, 27 were enrolled (75% recruitment rate; age: 16.5 ± 1.7 years, HbA1c: 6.6 ± 0.9%, 22/27 [81%] Hispanic, 17/27 [63%] female, 23/27 [85%] public insurance; all p-values >.05), and 23 of 27 completed the protocol.

INTERVENTION

Participants wore a continuous glucose monitor (CGM) daily and were randomized to one of two meal-timing schedules for 12-weeks: (1) lTRE (eating all food between 12:00 PM and 20:00 PM without calorie counting or recommended daily caloric intake) or (2) Control (eating over a period of 12 or more hours per day).

MAIN OUTCOME MEASURES

Study recruitment, retention and adherence to intervention arms were captured to operationalize feasibility. Glucose control (HbA1c), weight loss (%BMIp95), total body fat mass on DEXA, sleep, and dietary intake were explored as secondary outcomes.

STATISTICAL ANALYSIS

Analyses were based on the intention to treat (ITT) population. Between-group differences in clinical outcomes were assessed using mixed-effects longitudinal regression models.

RESULTS

Overall adherence to the 8-hr lTRE was 6.2 ± 1.1 d/wk and Control was 5.9 ± 0.9 d/wk. Participants assigned to lTRE indicated that limiting their eating window did not negatively affect their daily functioning and no adverse events were reported. In this pilot study, lTRE led to a reduction in %BMIp95 (-3.4%-95%CI:‒6.1, ‒0.7, p = 0.02), HbA1c (-0.4%, 95%CI:‒0.9, ‒0.01, p = .06), and ALT (-31.1 U/L, 95%CI:‒60, ‒2, p = .05) within the group. There was no significant difference observed between lTRE and control across these measures (all p > .05). The lTRE group had a ‒271.4 (95% CI, ‒565.2, 5.2) kcal/day energy reduction compared to a +293.2 (95% CI: 30.4, 552.7) kcal/day increase in Control (p = .01). There were no significant changes observed in sleep or eating behaviors over the study period between groups.

CONCLUSIONS

Recruitment and retention rates suggest a trial of lTRE in adolescents with T2D was feasible. lTRE was seen as acceptable by participants and adherence was high. A revised intervention, building on the successful elements of this pilot alongside adapting implementations strategies to augment adherence and engagement, should therefore be considered.

When a calorie is not just a calorie: Diet quality and timing as mediators of metabolism and healthy aging

An epidemic of obesity has affected large portions of the world, increasing the risk of developing many different age-associated diseases, including cancer, cardiovascular disease, and diabetes. In contrast with the prevailing notion that "a calorie is just a calorie," there are clear differences, within and between individuals, in the metabolic response to different macronutrient sources. Recent findings challenge this oversimplification; calories from different macronutrient sources or consumed at different times of day have metabolic effects beyond their value as fuel. Here, we summarize discussions conducted at a recent NIH workshop that brought together experts in calorie restriction, macronutrient composition, and time-restricted feeding to discuss how dietary composition and feeding schedule impact whole-body metabolism, longevity, and healthspan. These discussions may provide insights into the long-sought molecular mechanisms engaged by calorie restriction to extend lifespan, lead to novel therapies, and potentially inform the development of a personalized food-as-medicine approach to healthy aging.

Snacking Consumption among Adults in the United States: A Scoping Review

Snacks are a staple of the American diet, contributing to approximately 20% of energy intake. Most U.S. adults consume one to three snacks/day, yet few reviews have focused on snacking among this population. This scoping review was conducted to characterize snacks and snacking occasions among U.S. adults to further inform healthy eating practices. The protocol was prepared following the PRISMA-Extension for Scoping Reviews. Three web databases were used to identify articles using snacking or eating occasions as primary or secondary outcomes among U.S. adults. A search strategy was developed using subject headings, truncation, and phrase searching in the title and abstract of articles published between 2010 and 2022. A two-stage, multi-step screening process identified 31 of 4795 publications as meeting the inclusion criteria. Findings included identification of snacking themes, e.g., cues and motivations; diet composition; and weight management. Food quality, time of consumption, and convenience emerged as characteristics of snacking; time of day was found to influence food choice. Snacks contribute to or detract from a healthy diet. Strategic selection of healthy snack options can improve diet quality. Applied to nutrition education, this information can help strengthen programs or policies, ultimately contributing to health and wellbeing.

Impact of early time-restricted eating on diet quality, meal frequency, appetite, and eating behaviors: A randomized trial

OBJECTIVE

Time-restricted eating (TRE) can reduce body weight, but it is unclear how it influences dietary patterns and behavior. Therefore, this study assessed the effects of TRE on diet quality, appetite, and several eating behaviors.

METHODS

Adults with obesity were randomized to early TRE plus energy restriction (eTRE + ER; 8-hour eating window from 7:00 a.m. to 3:00 p.m.) or a control eating schedule plus energy restriction (CON + ER; ≥12-hour window) for 14 weeks. Food intake was assessed via the Remote Food Photography Method, while eating patterns, appetite, and eating behaviors were assessed via questionnaires.

RESULTS

A total of 59 participants completed the trial, of whom 45 had valid food records. eTRE + ER did not affect eating frequency, eating restraint, emotional eating, or the consistency of mealtimes relative to CON + ER. eTRE + ER also did not affect overall diet quality. The intensity and frequency of hunger and fullness were similar between groups, although the eTRE + ER group was hungrier while fasting.

CONCLUSIONS

When combined with a weight-loss program, eTRE does not affect diet quality, meal frequency, eating restraint, emotional eating, or other eating behaviors relative to eating over more than a 12-hour window. Rather, participants implement eTRE as a simple timing rule by condensing their normal eating patterns into a smaller eating window.

Integration of Time-Based Recommendations with Current Pediatric Health Behavior Guidelines: Implications for Obesity Prevention and Treatment in Youth

PURPOSE OF REVIEW

Youth-onset obesity is associated with negative health outcomes across the lifespan including cardiovascular diseases, type 2 diabetes, obstructive sleep apnea, dyslipidemias, asthma, and several cancers. Pediatric health guidelines have traditionally focused on the quality and quantity of dietary intake, physical activity, and sleep.

RECENT FINDINGS

Emerging evidence suggests that the timing (time of day when behavior occurs) and composition (proportion of time spent allocated to behavior) of food intake, movement (i.e., physical activity, sedentary time), and sleep may independently predict health trajectories and disease risks. Several theoretically driven interventions and conceptual frameworks feature behavior timing and composition (e.g., 24 h movement continuum, circadian science and chronobiology, intermittent fasting regimens, structured day hypothesis). These literatures are, however, disparate, with little crosstalk across disciplines. In this review, we examine dietary, sleep, and movement guidelines and recommendations for youths ages 0-18 in the context of theoretical models and empirical findings in support of time-based approaches. The review aims to inform a unifying framework of health behaviors and guide future research on the integration of time-based recommendations into current quantity and quality-based health guidelines for children and adolescents.

The Fasting and Shifted Timing (FAST) of Eating Study: A pilot feasibility randomized crossover intervention assessing the acceptability of three different fasting diet approaches

BACKGROUND AND AIMS

The aim of this study is to assess the acceptability of following three different fasting protocols [Early Time-restricted Feeding (eTRF; eating majority of kcals before 5pm), Time-restricted Feeding (TRF; restricting feeding window to 8 h/d), or Alternate Day Fasting (ADF; complete fasting every other day)].

METHODS

In this remotely delivered six-week crossover intervention, participants were randomly assigned to follow either an eTRF, TRF, or ADF diet for one week, followed by a one-week washout period. Participants followed all three diets and completed questionnaires assessing self-reported weight, energy intake, dietary acceptability (Food Acceptability Questionnaire), and facilitators and barriers to adhering to each diet. Differences in main outcomes (e.g., dietary acceptability and weight loss) were assessed via repeated measures ANOVA.

RESULTS

A total of 32 of participants began the study (mean BMI of 32.6 ± 6.0 kg/m²). There were no differences in kcals or weight loss among the three diets. Dietary acceptability was higher on the TRF diet (54.1 ± 8.2) than the eTRF (50.2 ± 6.6, p = 0.02) or ADF (48.0 ± 7.9, p = 0.004) diets. The majority of participants (71%) indicated the TRF diet was the easiest to follow and 75% said that ADF was the most difficult. Participants cited having a mobile app to track their diet and being provided with menu plans would help facilitate adherence with their diets.

CONCLUSIONS

This study found that acceptability was highest for an TRF diet and lowest for ADF, with no differences in weight loss or change in energy intake among the TRF, ADF, or eTRF groups.

CLINICAL TRIALS

GOV IDENTIFIER

NCT04527952.

Early time-restricted eating compared with daily caloric restriction: A randomized trial in adults with obesity

OBJECTIVE

This trial aimed to evaluate the acceptability and efficacy of early time-restricted eating plus daily caloric restriction (E-TRE+DCR) compared with DCR alone within a behavioral weight-loss intervention.

METHODS

Participants (n = 81, 69 women, mean [SD] age: 38.0 [7.8] years, BMI: 34.1 [5.7] kg/m² ) were randomized to E-TRE (10-hour eating window starting within 3 hours of waking) plus DCR or DCR alone (~35% DCR) for 39 weeks. The primary outcome was body weight (measured with digital scale) at week 12. Secondary outcomes measured at week 12 included hemoglobin A1c, lipids, energy intake (photographic food records), physical activity (accelerometry), dietary adherence (questionnaires), and body composition (dual-energy x-ray absorptiometry). Weight and body composition were also assessed at week 39.

RESULTS

Mean [SD] weight loss was not different between groups at week 12 (E-TRE+DCR: -6.2 [4.1] kg vs. DCR: -5.1 [3.2] kg) or at week 39 (E-TRE: -4.9 [5.3] kg vs. DCR: -4.3 [5.3] kg). There were no between-group differences in changes in body composition, dietary adherence, energy intake, physical activity, hemoglobin A1c, or lipids at week 12.

CONCLUSIONS

E-TRE+DCR was found to be an acceptable dietary strategy, resulting in similar levels of adherence and weight loss compared with DCR alone.

Assessing temporal eating pattern in free living humans through the myCircadianClock app

The quality and quantity of nutrition impact health. However, chrononutrition, the timing, and variation of food intake in relation to the daily sleep-wake cycle are also important contributors to health. This has necessitated an urgent need to measure, analyze, and optimize eating patterns to improve health and manage disease. While written food journals, questionnaires, and 24-hour dietary recalls are acceptable methods to assess the quantity and quality of energy consumption, they are insufficient to capture the timing and day-to-day variation of energy intake. Smartphone applications are novel methods for information-dense real-time food and beverage tracking. Despite the availability of thousands of commercial nutrient apps, they almost always ignore eating patterns, and the raw real-time data is not available to researchers for monitoring and intervening in eating patterns. Our lab developed a smartphone app called myCircadianClock (mCC) and associated software to enable long-term real-time logging that captures temporal components of eating patterns. The mCC app runs on iOS and android operating systems and can be used to track multiple cohorts in parallel studies. The logging burden is decreased by using a timestamped photo and annotation of the food/beverage being logged. Capturing temporal data of consumption in free-living individuals over weeks/months has provided new insights into diverse eating patterns in the real world. This review discusses (1) chrononutrition and the importance of understanding eating patterns, (2) the myCircadianClock app, (3) validation of the mCC app, (4) clinical trials to assess the timing of energy intake, and (5) strengths and limitations of the mCC app.

Time-restricted Eating for the Prevention and Management of Metabolic Diseases

Time-restricted feeding (TRF, animal-based studies) and time-restricted eating (TRE, humans) are an emerging behavioral intervention approach based on the understanding of the role of circadian rhythms in physiology and metabolism. In this approach, all calorie intake is restricted within a consistent interval of less than 12 hours without overtly attempting to reduce calories. This article will summarize the origin of TRF/TRE starting with concept of circadian rhythms and the role of chronic circadian rhythm disruption in increasing the risk for chronic metabolic diseases. Circadian rhythms are usually perceived as the sleep-wake cycle and dependent rhythms arising from the central nervous system. However, the recent discovery of circadian rhythms in peripheral organs and the plasticity of these rhythms in response to changes in nutrition availability raised the possibility that adopting a consistent daily short window of feeding can sustain robust circadian rhythm. Preclinical animal studies have demonstrated proof of concept and identified potential mechanisms driving TRF-related benefits. Pilot human intervention studies have reported promising results in reducing the risk for obesity, diabetes, and cardiovascular diseases. Epidemiological studies have indicated that maintaining a consistent long overnight fast, which is similar to TRE, can significantly reduce risks for chronic diseases. Despite these early successes, more clinical and mechanistic studies are needed to implement TRE alone or as adjuvant lifestyle intervention for the prevention and management of chronic metabolic diseases.