Time-Restricted Eating as a Nutrition Strategy for Individuals with Type 2 Diabetes: A Feasibility Study

Abstract

Individuals with type 2 diabetes (T2D) require a long-term dietary strategy for blood glucose management and may benefit from time-restricted eating (TRE, where the duration between the first and last energy intake is restricted to 8–10 h/day). We aimed to determine the feasibility of TRE for individuals with T2D. Participants with T2D (HbA1c >6.5 to <9%, eating window >12 h/day) were recruited to a pre-post, non-randomised intervention consisting of a 2-week Habitual period to establish baseline dietary intake, followed by a 4-weeks TRE intervention during which they were instructed to limit all eating occasions to between 10:00 and 19:00 h on as many days of each week as possible. Recruitment, retention, acceptability, and safety were recorded throughout the study as indicators of feasibility. Dietary intake, glycaemic control, psychological well-being, acceptability, cognitive outcomes, and physiological measures were explored as secondary outcomes. From 594 interested persons, and 27 eligible individuals, 24 participants enrolled and 19 participants (mean ± SD; age: 50 ± 9 years, BMI: 34 ± 5 kg/m2, HbA1c: 7.6 ± 1.1%) completed the 6-week study. Overall daily dietary intake did not change between Habitual (~8400 kJ/d; 35% carbohydrate, 20% protein, 41% fat, 1% alcohol) and TRE periods (~8500 kJ/d; 35% carbohydrate, 19% protein, 42% fat, 1% alcohol). Compliance to the 9 h TRE period was 72 ± 24% of 28 days (i.e., ~5 days/week), with varied adherence (range: 4–100%). Comparisons of adherent vs. non-adherent TRE days showed that adherence to the 9-h TRE window reduced daily energy intake through lower absolute carbohydrate and alcohol intakes. Overall, TRE did not significantly improve measures of glycaemic control (HbA1c −0.2 ± 0.4%; p = 0.053) or reduce body mass. TRE did not impair or improve psychological well-being, with variable effects on cognitive function. Participants described hunger, daily stressors, and emotions as the main barriers to adherence. We demonstrate that 4-weeks of TRE is feasible and achievable for these individuals with T2D to adhere to for at least 5 days/week. The degree of adherence to TRE strongly influenced daily energy intake. Future trials may benefit from supporting participants to incorporate TRE in regular daily life and to overcome barriers to adherence.

Food Timing, Circadian Rhythm and Chrononutrition: A Systematic Review of Time-Restricted Eating’s Effects on Human Health

“…Preliminary research identified four hundred and ninety-four articles, including clinical trials, literature reviews and other relevant work. After the exclusion of one hundred and six duplicates, three hundred and eighty-eight articles remained, from which 22 have been finally selected [ 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 ]. An article was added during the full article reading stage (R15—[ 41 ]), making a total of 23 articles included for analysis (see flow chart in Figure 1 ).…”

Pilot Clinical Trial of Time-Restricted Eating in Patients with Metabolic Syndrome

“…To our knowledge, one pilot study of an American population of patients with diagnosed MetS [ 34 ] and several small-scale TRE trials in the populations (mainly from the US) with elevated BMI (overweight or obese subjects) [ 25 , 35 , 36 , 37 , 38 , 40 , 41 , 42 , 44 , 45 , 46 ], increased waist circumference (individuals with central obesity) [ 39 , 40 , 43 ], and disorders of glucose metabolism (subjects with prediabetes, high risk of T2DM, and T2D with controlled hyperglycemia (HbA1c < 9%) either by diet or taking ≤ two oral hypoglycemic agents) [ 37 , 39 , 47 ] were conducted. The trials of individuals with metabolic disorders demonstrated that TRE result in several cardiometabolic benefits such as weight loss [ 25 , 34 , 35 , 38 , 39 , 40 , 43 , 44 ] and a decrease in body fat [ 34 , 35 , 36 , 43 , 44 ] and energy intake [ 25 , 34 , 36 , 38 , 44 , 47 ], as well as improved glucose tolerance [ 39 ], insulin resistance [ 37 , 38 , 41 , 44 ], glycemic control [ 35 , 36 , 39 , 41 , …”

“…In the pilot study of American patients with MetS, the improvements in body weight and fat, waist circumference, atherogenic lipids, and BP were observed despite no overt attempt to change diet quantity and quality or physical activity [ 34 ]. Moreover, previous TRE trials of subjects with metabolic disorders reported good adherence with TRE for a period up to 16 weeks [ 25 , 34 , 35 , 38 , 43 , 47 ].…”

“…In the pilot study of American population with MetS, the adherence to TRE and mCC app during a 12-week period was shown to be ~90 and ~85%, respectively [ 34 ]. In the study of diabetic patients, the rate of adherence varied greatly from 4% to 100% even over a relatively short period of 4-week TRE intervention [ 47 ]. This indicates that the adherence to TRE can be variable and is not always satisfactory.…”

“…One pilot TRE study (19 patients) provides results that are specific to American population with diagnosed MetS [ 34 ]. Several small-scale human studies of individuals with various metabolic disorders but without overt metabolic disease, as well as a feasibility study of obese patients with T2D, suggest usefulness of TRE for improving cardiometabolic health [ 25 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 ]. It has been demonstrated that TRE can be feasible and effective for weight loss and a decrease in body fat and energy intake, as well as improvements in glucose tolerance, insulin resistance, glycemic control, lipid levels, sleep, quality of life, and BP.…”