What does the evidence say about time-restricted eating with calorie restriction as compared with daily calorie restriction alone for the effects on weight loss and metabolic risk factors in obese patients?

Comment by InpharmD Researcher

Successful weight loss was seen in patients with obesity, regardless of whether they reduced their calorie consumption through time-restricted eating or through calorie restriction alone.
Background

The Academy of Nutrition and Dietetics recommends the caloric need for adult women ranges from 1600 to 2200 per day, and for adult men from 2000 to 3200. [1]

According to pre-clinical studies, time-restricted eating (TRE) can reduce body weight, improve glucose tolerance, protect from hepatosteatosis, increase metabolic flexibility, reduce atherogenic lipids and blood pressure, and improve gut function and cardiometabolic health. Human trials assessing TRE found the following major findings: decrease in body weight, decrease in fat mass, decrease in blood pressure, and a decrease in glucose tolerance. However, these studies are limited in number, sample size, and study duration. [2]

References:

1. Klemm CS. How many calories do adults need? EatRight. https://www.eatright.org/food/nutrition/dietary-guidelines-and-myplate/how-many-calories-do-adults-need. Accessed June 21, 2022.



2. Regmi P, Heilbronn LK. Time-Restricted Eating: Benefits, Mechanisms, and Challenges in Translation. iScience. 2020;23(6):101161. doi:10.1016/j.isci.2020.101161

Literature Review

A search of the published medical literature revealed 1 study investigating the researchable question:

What does the evidence say about time-restricted eating with calorie restriction as compared with daily calorie restriction alone for the effects on weight loss and metabolic risk factors in obese patients?

Level of evidence

B - One high-quality study or multiple studies with limitations  Read more→


Please see Table 1 for your response.

 

 

Calorie Restriction with or without Time-Restricted Eating in Weight Loss

Design

Randomized clinical trial 

N= 139

Objective

To assess time-restricted eating with calorie restriction as compared with daily calorie restriction alone for the effects on weight loss and metabolic risk factors in obese patients.

Study Groups

Time-restricted eating group: n= 69

Daily calorie restriction group: n= 70

Inclusion Criteria

18 to 75 years of age and had a body-mass index between 28 and 45

Exclusion Criteria

acute or chronic viral hepatitis, malignant tumors, diabetes, serious liver dysfunction or chronic kidney disease, current smoking, serious cardiovascular or cerebrovascular disease within 6 months before randomization, severe gastrointestinal diseases or gastrointestinal surgery in the 12 months before randomization, active participation in a weight-loss program, use of medications that affect weight or energy balance, and current or planned pregnancy

Methods

Patients were randomized into the time-restricted eating group or the daily calorie restriction group. 

Men were instructed to follow 1500 to 1800 kcal/day diet and women 1200 to 1500 kcal/day. Participants were provided with one protein shake, a diet appropriate convenience food, per day for the first six months to help improve adherence to the permitted calorie intake. All participants received dietary counseling for the duration of the trial. 

Participants in the time-restricted–eating group were instructed to consume the prescribed calories within an 8-hour period (from 8:00 a.m. to 4:00 p.m.) each day. Only noncaloric beverages were permitted outside of the 8-hour daily eating period. Participants in the daily-caloriere striction group were instructed to consume the prescribed calories without time restriction.

During the first 6 months of the trial, all the participants were required to write in a daily dietary log, photograph the food they ate, and note the time at which they ate with the use of a custom mobile study application. During the second 6 months of the trial, participants were instructed to maintain their diet regimens and to fill out their dietary logs and record food pictures and meal times 3 days per week.

Adherence to the dietary program was defined according to the number of days that a participant met the requirements of the assigned diet.

Duration

12-month trial 

Outcome Measures

Primary outcome: the difference between the two groups in the change from baseline in body weight at 12 months

Secondary outcomes: changes in waist circumference, body fat, body lean mass, and metabolic risk factors, including levels of plasma glucose, insulin sensitivity, serum lipids, and blood pressure

Baseline Characteristics 
Variables Time-Restricted Eating
(N=69)		 Daily Calorie Restriction
(N=70)
Male sex — no. (%) 36 (52.2) 35 (50.0)
Age — yr 31.6±9.3 32.2±8.8
Body weight — kg 88.4±10.2 87.9±12.8
Body-mass index 31.8±2.9 31.3±2.6
Body fat mass — kg 33.0±7.3 33.2±6.3
Body lean mass — kg 51.2±7.8 50.9±9.1
Body fat — % 38.3±5.5 38.4±5.3
Waist circumference — cm 99.4±7.8 99.2±9.1
Median (IQR) abdominal fat area — cm2  
Visceral 122.3 (97.2–159.7) 124.9 (91.4–160.0)
Subcutaneous 312.8 (264.5–386.3) 302.9 (248.0–360.4)
Blood pressure — mm Hg  
Systolic 125.3±12.0 124.8±12.2
Diastolic 73.1±9.5 74.5±9.6
Pulse — beats/min 78.6±11.7 79.1 ±10.3
Glucose — mg/dl 90.9±11.0 92.1±17.1
Glycated hemoglobin — % 5.3±0.4 5.4±0.8
Median (IQR) HOMA–IR index value 3.4 (2.4–5.1) 3.3 (2.0–4.4)
Cholesterol — mg/dl  
Total 194.5±32.9 198.0±37.8
High-density lipoprotein 46.1±10.2 45.1±12.7
Low-density lipoprotein 130.7±29.9 129.6±33.7
Median (IQR) triglycerides — mg/dl 130.2 (86.8–173.7) 137.3 (107.2–185.2)
Dyslipidemia — no. (%) 48 (69.6) 53 (75.7)
Hypertension — no. (%) 11 (15.9) 12 (17.1)
Total caloric intake — kcal/day 2052.5±341.7 2075.7±391.5
Daily eating window — hr:min 10:23±01:25 10:24±01:34
Median (IQR) physical activity — METs per wk 12.0 (8.3–23.6) 15.0 (8.0–23.1)
SF-12 score  
Physical component summary 45.3±7.1 46.4±6.6
Mental component summary 53.2 ±7.1 53.2±6.9

Results 
  Time-Restricted Eating
(N=69)		 Daily Calorie Restriction
(N=70)		 Difference between Groups
(95% CI)
  Change from baseline (95% CI)  
Body weight — kg   
6 mo −9.4 (−10.8 to −7.9) −8.9 (−10.3 to −7.4) −0.5 (−2.6 to 1.6)
12 mo −8.0 (−9.6 to −6.4) −6.3 (−7.8 to −4.7) −1.8 (−4.0 to 0.4)
Body-mass index   
6 mo −3.4 (−3.9 to −2.9) −3.2 (−3.7 to −2.7) −0.2 (−1.0 to 0.5)
12 mo −2.9 (−3.5 to −2.3) −2.3 (−2.8 to −1.7) −0.7 (−1.5 to 0.1)
Waist circumference — cm   
6 mo −9.4 (−11.0 to −7.9) −8.7 (−10.2 to −7.3) −0.7 (−2.8 to 1.4)
12 mo −8.8 (−10.4 to −7.1) −7.0 (−8.5 to −5.4) −1.8 (−4.0 to 0.5)
Body fat mass — kg   
6 mo −6.9 (−8.0 to −5.7) −6.4 (−7.5 to −5.3) −0.5 (−2.0 to 1.1)
12 mo −5.9 (−7.1 to −4.7) −4.5 (−5.6 to −3.3) −1.5 (−3.1 to 0.2)
Body lean mass — kg   
6 mo −1.9 (−2.4 to −1.4) −1.7 (−2.2 to −1.2) −0.2 (−0.9 to 0.5)
12 mo −1.7 (−2.3 to −1.1) −1.4 (−2.0 to −0.9) −0.3 (−1.1 to 0.5)
Body fat percent — %   
6 mo −4.7 (−5.6 to −3.8) −4.4 (−5.3 to −3.5) −0.3 (−1.6 to 1.0)
12 mo −4.3 (−5.3 to −3.3) −3.0 (−3.9 to −2.0) −1.3 (−2.7 to 0.1)
Area of abdominal visceral fat — cm2   
6 mo −32.9 (−41.1 to -24.8) −31.3 (−39.2 to −23.4) −1.7 (−13.0 to 9.7)
12 mo −26.0 (−35.0 to −17.1) −21.1 (−29.5 to −12.8) −4.9 (−17.3 to 7.5)
Area of abdominal subcutaneous fat — cm2   
6 mo −70.1 (−85.2 to −55.1) −49.2 (−64.1 to −34.4) −20.9 (−42.0 to 0.2)
12 mo −53.2 (−71.9 to −34.6) −37.0 (−52.1 to −21.9) −16.2 (−39.2 to 6.8)

Study Author Conclusions

The weight loss regimens were successful in patients with obesity, regardless of whether they reduced their calorie consumption through time-restricted eating or through calorie restriction alone.

InpharmD Researcher Critique

Time-restricted weight loss does not significantly make a difference. 



References:

Liu D, Huang Y, Huang C, et al. Calorie restriction with or without time-restricted eating in weight loss. N Engl J Med. 2022;386(16):1495-1504.