Table 1.
Studies evaluating the effects of fasting diets on eating behaviors.
| Study (ref.) | Population | Fasting type & regimen | Time of treatment | Findings |
|---|---|---|---|---|
| Keenan (25) 2022 Australia | Both sexes BMI range: 22–35 kg/m2 Age range: 18–35 y 5:2 diet + Exercise group: n = 17 CR diet + Exercise group: n = 17 |
5:2 diet + Exercise: 2 d fasting (restriction of 70% E + TRF between 12 p.m. and 6 p.m.); 5 d feeding (Euenergetic consumption); 3 resistance training sessions/week CR diet + Exercise: 20% E restriction; 3 resistance training sessions/week In both groups: Energy intake = approximately 80% E per day and pro intake ≥1.4 gr/kg/d |
3 months | Hunger: ↓ 5:2 diet + Exercise, ↓ CR diet + Exercise Craving: ↔ 5:2 diet + Exercise, ↔ CR diet + Exercise |
| Kalam (26) 2021 United States | Both sexes BMI range: 30–50 kg/m2 Age range: 18–65 y n = 31 |
ADF: consuming 600 kcal on fasting days and usual diets on feed days; 30 E% carbohydrates; 35 E% protein and 35 E% fat | 6 months | ↔ Fasting and postprandial hunger ↔ Fasting and postprandial fullness |
| Teong (27) 2021 Australia | Women BMI range: 25–42 kg/m2 Age range: 30–70 y ADF group: n = 22 CR group: n = 23 |
ADF group: consuming 30% E requirement as breakfast at 8 a.m. on fasting days and fasted for 24 h and usual diets on feed days CR: consuming 70% E requirement |
2 months | Dietary restraint, disinhibition or hunger: ↔ Both groups Depression, anxiety or stress, and sleep quality: ↔ Both groups |
| Oustric (28) 2021 United Kingdom | Women BMI 25.0–34.9 kg/m2 Age range: 18–55 y ADF group: n = 19 CR group: n = 18 |
ADF group: consuming 30% E requirement and usual diets on feed days CR: consuming 75% E requirements |
3 months | Liking for high fat-sweet, high-fat-savory, low-fat-sweet and low-fat-savory: ↓ ADF, ↓ CR Wanting for high fat-sweet, high-fat-savory, low-fat-sweet and low-fat-savory: ↔ ADF, ↔ CR |
| Beaulieu (29) 2020 United States | Women BMI range: 25–34.9 kg/m2 Age range: 18–55 y ADF group: n = 24 CR group: n = 22 |
ADF group: consuming 25% E requirement on fasting days and usual diets on feed days CR group: consumption of 75% E needs per day |
Reaching to ≥5% weight loss, in ADF group: about 67 days, in CR group: about 57 days | Hunger: ↓ ADF, ↓ CR Satiety: ↔ ADF, ↔ CR Dietary restraint: ↓ ADF, ↓ CR Desire to eat: ↓ ADF, ↓ CR Disinhibition: ↑ ADF, ↓ CR Susceptibility to hunger: ↓ ADF, ↓ CR Binge eating scores: ↓ ADF, ↓ CR Craving for sweet foods: ↓ ADF, ↓ CR Craving for savory foods: ↑ ADF, ↓ CR Food reward (Liking and wanting for high-fat relative to low-fat): ↔ ADF, ↔ CR |
| Ravussin (30) 2019 United States | Both sexes BMI range: 25–35 kg/m2 Age range: 20–45 y n = 10 |
TRF: eat between 8:00–14:00; 6 h daily eating period for 4 days and then to cross over to the other arm after a 3.5–5 weeks washout period Control group: eat between 8:00–20:00 h; 12 h daily eating period |
4 days | Hunger: ↔ TRF, ↓ Control group Fullness: ↑ TRF, ↔ Control group Desire to eat: ↓ TRF, ↓ Control group |
| Hutchison (31) 2019 Australia | Men Mean BMI: 33.9 ± 0.8 kg/m2 Age range: 30–70 y n = 15 |
Early TRF: time restricted eating from 8 a.m. to 5 p.m. Delayed TRF: time restricted eating from 12 p.m. to 9 p.m., separated by a 2 weeks washout phase |
7 days | Hunger, fullness, and desire to eat: ↔Early TRF, ↔Delayed TRF |
| Sutton (32) 2018 United States | Men with prediabetes BMI: 32.2 ± 4.4 kg/m2 Mean age = 56 ± 9 n = 8 |
TRF: 6 h feeding period, with dinner before 3 p.m., with 18 h of daily fasting. Control group:12 h feeding period |
5 weeks | Desire to eat in the evening ↓ TRF Fullness in the evening ↑ TRF |
| Kroeger (33) 2018 United States | Both sexes BMI range: 25–40 kg/m2 Age range: 18–65 y ADF group: n = 34 ADF with ≥5% weight-loss: n = 14 ADF with weight-loss <5%: n = 20 CR group: n = 35 CR with ≥5% weight-loss: n = 14 CR with weight-loss <5%: n = 21 |
Weight loss phase ADF group: consuming 25% E requirement on fasting days and 125% E requirement on feed days CR group: consumption of 75% E needs per day Weight maintenance phase ADF group: consuming 50% E requirement on fasting days and 150% E requirement on feed days CR group: consumption of 100% E needs per day |
12 months 6 months weight loss phase and 6 months weight maintenance phase |
Hunger: ↓ ADF with ≥5% weight-loss after/before ↔ ADF with weight-loss <5% after/before ↔ CR group after/before Fullness: ↓ ADF with ≥5% weight-loss after/before ↔ ADF with weight-loss <5% after/before ↔ CR group after/before Restrained eating and self-efficacy: ↔ in all groups |
| Coutinho (34) 2018 Norway | Both sexes BMI range: 30 < BMI < 40 kg/m2 Age range: 18–65 y ADF group: n = 18 CR group: n = 17 |
ADF group: consuming 550 and 660 kcal/day for women and men, respectively, on fasting days and habitual diet on feed days CR group: conventional calorie diet |
3 months | Hunger, Fullness, Desire to eat: ↔ Both groups |
| Hoddy (35) 2016 Hoddy (36) 2015 United States |
Both sexes BMI range: 30–39.9 kg/m2 Age range: 25–65 y n = 59 |
ADF group: consuming 25% E requirement on fasting days and habitual diets on feeding days | 2 months | Hunger:↔ Fullness:↑ Restrictive eating:↑ Avoidance of forbidden foods:↔ |
| Bhutani (37) 2013 United States | Women BMI range: 30–39.9 kg/m2 Age range: 25–65 y ADF group: n = 25 Exercise group: n = 24 Combination (ADF + exercise): n = 18 Control: n = 16 |
ADF group: consuming 25% E requirement on fasting days + TRF between 12 p.m. and 2 p.m. and habitual diets on feeding days Exercise group: moderate intensity exercise program 3 times/week Combination group (ADF + Exercise): consuming 25% of energy requirement on fasting days and habitual diets on feeding days + TRF between 12 p.m. and 2 p.m. Control group: habitual diet |
3 months | Hunger: ↓ ADF ↔ Combination Satisfaction and fullness: ↑ ADF ↔ Combination Restrained eating score: ↑ ADF, ↑ Combination ↔ Exercise, ↔ Control Uncontrolled eating score: ↓ ADF, ↓ Combination ↔ Exercise, ↔ Control Emotional eating score: ↔ ADF, ↓ Combination ↔ Exercise, ↔ Control |
| Varady (38) 2013 United States | Both sexes BMI range: 20–29.9 kg/m2 Age range: 35–65 y ADF group: n = 16 Control: n = 15 |
ADF group: consuming 25% E requirement on fasting days + TRF between 12 p.m. and 2 p.m. and habitual diets on feeding days Control group: habitual diet |
3 months | Satisfaction ↑ ADF group, ↔ Control group Fullness ↑ ADF group, ↔ Control group |
| Moreno-Domínguez (39) 2012 Spain | Women Healthy women: n = 20 Bulimia nervosa participants: n = 21 |
Fating for 20 h | 20 h | Food cravings ↑ Both groups |
| Klempel (40) 2010 United States | Both sexes BMI range: 30–39.9 kg/m2 Age range: 35–65 y n = 16 |
ADF group: consuming 25% of energy requirement on fasting days and habitual diets on feeding days | 2 months | Hunger: ↑ During the first week ↓ The rest of the trial Satisfaction: ↓ During the first week ↑ During the last 4 weeks of the study. Fullness: ↓ During the entire 8-week intervention |
| Johnson (41) 2007 United States | Both sexes Asthma patients BMI >30 kg/m2 n = 10 |
ADF group: consuming 320 calories in women and men 380 calories in men on fasting days and habitual diets on feeding days | 2 months | Hunger: ↔ |
| Heilbronn (42) 2005 United States | Both sexes BMI range: 20–30 kg/m2 Age range: 25–53 y n = 16 |
ADF group: 24 h fasting on fasting days and habitual diet on feed days | 22 days | Hunger: ↓ Fullness: ↑ |
| Finch (43) 1998 United Kingdom | Both sexes Age range: 13–63 y n = 41 |
Fasting hours were about 13–15 h/d for more than 21 d during the Ramadan | 1 month | Hunger: ↑ During the daily fast, ↑ women > men during the earlier days of Ramadan Desire to eat sweet: ↑ women > men |
ref, reference; BMI, body mass index; y, year: E%, energy%; CR, calorie restriction; d, day; ADF, alternate day fasting; hr: hours; TRF: time-restricted feeding; ↑, increased; ↓, decreased; ↔, without change.