Table 2.
Acute and chronic effects of alternative-day fasting, alternative-day modified fasting, and twice-weekly fasting on energy expenditure and substrate oxidation.
| Study | Population | Design | Fasting Regimen | Eating Regimen | Assessment | No Change | Increase | Decrease |
|---|---|---|---|---|---|---|---|---|
| Acute alternative-day fasting | ||||||||
| [27] | Healthy normal weight/obesity n = 14 (14 M/0 F) |
48 h Cross-over (a) Control (b) ADF |
(2) 48 h fasting | (1) 100% Energy needs | Metabolic chamber |
AEE | 24 h EE and SEE 24 h RER |
|
| [83] | Healthy normal weight/obesity n = 64 (51 M/13 F) |
36 h Cross-over (a) Control (b) ADF |
(2) 36 h fasting | (1) 100% Energy needs | Metabolic chamber |
SEE | 24 h Fat ox. | 24 h EE 24 h RER and sleep RER 24 h CHO ox. 24 h Protein ox. |
| Chronic alternative-day fasting | ||||||||
| [75] | Healthy normal/overweight n = 8 (8 M/0 F) |
2-week Single-arm (1) ADF |
20 h fasting every other day (From 10 p.m. to 6 p.m.) |
Ad libitum | Overnight fasting Metabolic cart (Oxycon Pro, Jaeger) |
RER | ||
| [76] | Healthy normal/overweight n = 16 (8 M/8 F) |
22-day Single-arm (1) ADF |
24 h fasting every other day | Ad libitum | Overnight fasting Metabolic cart (DeltaTrac, SensorMedics) |
RMR and adjusted RMR * in fed and fast days RER, CHO and Fat ox. In fed day |
Fat ox. In fast day | RER and CHO ox. In fast day |
| [77] | Healthy normal/overweight n = 8 (8 M/0 F) |
2-week Cross-over (a) Control (b) ADF |
(2) 20 h fasting every other day (From 10 p.m. to 6 p.m.) |
1 and (2) 100% Energy needs | Overnight fasting Metabolic cart |
RER, CHO and Fat ox. | RMR | |
| [74] | Obesity (1) n = 12 (3 M/9 F) (2) n = 13 (3 M/10 F) |
8-week RCT (1) CR (2) ADF |
(2) 24 h fasting every other day | (1) Prescribed CR −400 kcal/day. Measure 28% CR (2) 100% Energy needs + ad libitum access to 5–7 snacks (200 kcal/serve) during eating days. Measure 47% CR |
Overnight fasting Metabolic cart (TrueOne 2400, Parvo Medics) |
RMR and adjusted RMR * | ||
| [78] | Healthy normal/overweight (1) n = 29 (12 M/17 F) (2) n = 28 (11 M/17 F) |
4-week RCT (1) Control (2) ADF |
(2) 24 h fasting every other day | (1) Ad libitum. Measured 8% CR (2) Ad libitum. Measured 37% CR |
Overnight fasting Metabolic cart (MetaMax 3b, Cortex) |
RMR | ||
| [78] | Healthy normal/overweight (1) n = 60 (24 M/36 F) (2) n = 30 (14 M/16 F) |
Observational (1) Control (2) ADF performed >24 weeks |
(2) 24 h fasting every other day | (1) Ad libitum. Measured 0% CR (2) Ad libitum. Measured 29% CR |
Overnight fasting Metabolic cart (MetaMax 3b, Cortex) |
RMR | ||
| [42] | Healthy normal/overweight (1) n = 12 (5 M/7 F) (2) n = 12 (3 M/9 F) (3) n = 12 (7 M/5 F) |
3-week RCT (1) CR (2) ADF without CR (3) ADF + CR |
2 and (3) 24 h fasting every other day | (1) Daily 25% CR (2) 200% Energy needs in fed days, 0% net CR (3) 150% Energy needs in fed days, 25% net CR |
Overnight fasting and 3-h postprandial period Metabolic cart |
RMR and adjusted RMR ¥ Fasting CHO, Fat and Protein ox. Postprandial CHO and Protein ox. |
Postprandial Fat ox. in both ADF groups vs. CR | |
| Chronic alternative-day modified fasting | ||||||||
| [81] | Overweight/obesity (1) n = 10 (0 M/10 F) (2) n = 10 (0 M/10 F) (3) n = 10 (0 M/10 F) |
4-week Cross-over (a) CR (b) Bread ADMF (c) ADMF |
(2) Ad libitum bread, coffee and tea (3) 50% CR |
(1) Daily 50% CR (2) 100% Energy needs (3) 100% Energy needs |
Metabolic chamber |
Adjusted 24 h EE ¥ and AEE Adjusted SEE ¥ in CR vs. ADMF |
Adjusted SEE ¥ in ADMF vs. bread ADMF | |
| [80] | Obesity (1) n = 14 (4 M/10 F) (2) n = 14 (2 M/12 F) |
12-week RCT (1) CR (2) ADMF |
(2) EI of 660 and 550 kcal/day for men and women, respectively, on 3 non-consecutive days/week | (1) Daily 25% CR (2) 100% Energy needs |
Overnight fasting Metabolic cart (Vmax Encore 29N, Care Fusion) |
RMR and adjusted RMR α RER |
||
| [79] | Overweight/obesity (1) n = 18 (0 M/18 F) (2) n = 12 (0 M/12 F) |
RCT ≥ 5% WL within 12 weeks (1) CR (2) ADMF |
(2) 75% CR every other day | (1) Daily 25% CR (2) Ad libitum |
Overnight fasting Metabolic cart (GEMNutrition) |
RMR | ||
| Chronic twice-weekly fasting (2-WF) | ||||||||
| [54] | Overweight/obesity (1) n = 12 (6 M/6 F) (2) n = 15 (7 M/8 F) |
RCT 5% WL target (1) CR (2) 2-WF |
(2) 75% CR on two consecutive days/week | (1) Daily 33% CR (2) Ad libitum |
Overnight fasting Metabolic cart Φ (ISGEM319, GEMNutrition) |
RMR and adjusted RMR £ RER |
||
| [82] | Adults with central obesity (1) n = 22 (6 M/16 F) (2) n = 21 (6 M/15 F) |
4-week RCT (1) CR (2) 2-WF |
(2) EI of 600 kcal on two consecutive days/week | (1) Daily 500 kcal CR (2) Energy-controlled diet to target the same weekly energy deficit as the CR |
Overnight fasting Metabolic cart (FitMate, Cosmed) |
RMR | ||
| [55] | Healthy normal weight (1) n = 8 (4 M/4 F) (2) n = 8 (4 M/4 F) |
2-week RCT (1) CR (2) 2-WF |
(2) 70% CR on two non-consecutive days/week | (1) Daily 20% CR (2) 100% Energy needs |
Overnight fasting Metabolic cart (Quark CPFT, Cosmed) |
RMR RER |
||
No change indicates no significant difference to pre-intervention or control group values; increase indicates significantly higher than pre-intervention or control group values; and decrease indicates significantly lower than pre-intervention or control group values. * RMR results adjusted for fat-free mass and fat mass; ¥ RMR, 24 h EE or SEE results adjusted for body weight or fat-free mass; α RMR results adjusted for fat-free mass; £ RMR results adjusted for metabolically active mass (fat-free mass + 18 kg); Φ Sample size n = 10 and n = 13 for CR and twice-weekly fasting (2-WF), respectively. Metabolic cart brands and models are provided when they are available. Abbreviations: ADF, alternate-day fasting; ADMF, alternative-day fasting modified fasting; AEE, activity energy expenditure; CR daily calorie restriction; EE, energy expenditure; RER, respiratory exchange ratio; RMR, resting energy expenditure; SEE, sleeping energy expenditure; WL, weight loss.