Table 2 Characteristics of included trials
First Author/Year | Design | Duration | Sample size | Age, years (Mean, S.D., Range) | Sex | Population | Setting | Inclusion/Exclusion | Meals (n) | Eucaloric OR equicalorific | Energy deficit/balance/surplus |
|---|---|---|---|---|---|---|---|---|---|---|---|
Finkelstein—1971 [30] | Parallel trial | 2 × 30 day | 8 | 20–22 | Female | Overweight—no defined baseline | Mixed | No exclusions reported | 4 vs 6 | equicalorific—1700 then 1400 for kcals 1st and 2nd 30 days | Unclear (likely deficit) |
Young—1971 [31] | Crossover trial | 2 × 35 days | 12 | 22.2 (20–25) | Male | Overweight—no baselines | Free-living | No exclusions reported | 1 vs 3 vs 6 | equicalorific—1800kcals | Deficit |
Jenkins – 1989 [32] | Crossover trial | 2 × 14 days | 7 | 31–51 / 39.6 | Male | Normal—not specified how this was calculated (98–121% of normal) | Mixed | No exclusions reported | 3 vs 17 | eucaloric—Mean 2730 ± 189 kcals | Balanced |
Verboeket – 1993 [33] | Parallel trial | 28 days | 14 | 46.1 ± 3.3 (20–58) | Female | Overweight and Obese (BMI 30.2 ± 0.8 kg/m2) | Free living | Inclusion: Age 20–60; BMI 25–35 kg/m2 NO clear exclusion criteria | 2 vs 4 | equicalorific—1000 kcal MAX | Deficit |
Murphy – 1996 [34] | Crossover trial | 2 × 14 days | 11 | 21–24 | Female | Normal and overweight (BMI 23.6 ave; 20.6–27.2 range) | Free living | No exclusions reported | 2 vs 12 | equicalorific—2000kcals—not measured to activity or BMR | Unclear |
Rashidi – 2003 [35] | Crossover trial | 2 × 14 days | 15 | 27.2 ± 6.4 | Male | Unclear. Reported mean weight of 66.8 ± 11.1 | Free living | No exclusions reported | 3 vs 9 | Unclear | Unclear |
Crossover trial | 2 × 56 days | 21 | 45 ± 0.7 (40–50) | Both (10 female completers) | Normal | Mixed | Exclusions: smoking, pregnancy or lactation, history of Cardiovascular Disease (CVD) or medication use for CVD, Hypertension (HTN), Diabetes Mellitus (DM), psychiatric disorders, cancer, or high-risk occupations | 1 vs 3 | Eucaloric | Balance | |
Berteus-Forslund [38] | Parallel trial | 365 days | 140 | Each group. 40.6 ± 11.1 and 41.8 ± 11.0 | Both (27 male:66 female) | Obese | Free living | Inclusions: Age 18–60, BMI > 30. Exclusions: history of obesity surgery, anti-obesity drug treatment within a year; drug or insulin dependent diabetes; hypothyroidism; severe psychiatric disorder; bulimia; drug or alcohol abuse | 3 vs 6 | Eucaloric | Energy balance—min 1400kcals |
Cameron [39] | Parallel trial | 56 days | 18 | 18–55 | Both | Obese (BMI 30–45) | Free living | Inclusion: Obese, non-diabetic, non smokers, non pregnant, sedentary, weight stable > 6/12, Pre-menopausal | 3 vs 6 | Groups were prescribed a 700 kcal deficit. Neither equicalorific or eucaloric | Deficit |
Bachman [40] | Parallel trial | 182 days | 51 | 21–65 | Both | Overweight and obese (BMI 27–45) | Free living | Inclusion: Age, BMI. Exclusions: heart or chest condition, or concerns on Physical Activity Readiness Questionnaire (PAR-Q). Unable to walk 2 blocks. Psychiatric illness. DM type 1 or 2. Recent weight change or participation in weight loss program. Intention to leave Tennessee. Pregnant or Lactating or < 6/12 post partum. Consent withheld for group meetings or diary keeping | 3 vs 6 | Unclear—all running different kcal deficit—'Grazing' intervention averages 110 kcals higher overall | Deficit—either 1200 or 1500 kcals based upon body weight |
Arciero [41] | Parallel trial | 56 days | 30 | 46 ± 11/ 47 ± 9/ 45 ± 9 (45.9—9.4) | Both (4 male and 24 female) | Overweight and obese (BMI 30.3 ± 5.9) | Free living | Inclusions: Non-smoker; healthy men/women with no cardio or metabolic disorder; inactive < 30 min over 2/7 of structured physical activity, overweight or obese, middle-aged and weight stable (within 2 kg past 6/12) | 3 vs 3 high-protein vs 6 | Eucaloric | Balanced—RMR and PAL taken |
Hatami – 2014 [42] | Parallel trial | 90 days | 90 | 36.4 ± 9.7 | Both (72 – 80%—female) | Overweight/Obese—INT (mean BMI 30.9 ± 5.1): CON (mean BMI 30.3 ± 4.7) | Free living | Inclusion criteria: Age 20–60, not on cholesterol lowering medication, not on lipid-lowering or weight-controlled diet, free from potential causes of secondary hypercholesterolaemia (e.g. pregnancy, or hyperthyroidism), not on night shifts, non-smoker, and no chronic diseases (heart, kidney or cancer) | 6 vs 5 | Eucaloric | Deficit—given 400 kcals less than calculated daily requirement |
Alencar (Kulovitz) [43] | Crossover trial | 2 × 14 days | 11 | 52 ± 7 | Female | Obese | Free living | Inclusions: nondiabetic; sedentary to moderately active—30 min per day; weight stable; less that 4 meals/snacks per day habitually Exclusions: medications (diuretics); supplements including caffeine; pacemaker; smoker; bodyweight loss > 3 kg in 6/12; bariatric surgery; changed physical activity; pregnant or lactating; DM/thyroid/cancer/gastrointestinal issues of absorption/liver or kidney disease; allergies; unstable medications e.g. statin status; alcohol consumption | 2 vs 6 | Equicalorific 1200kcals p/day | Deficit |
Perrigue [44] | Crossover trial | 2 × 21 days | 15 | 28.5 ± 8.7 | Both (4 male:11 female) | Normal and overweight (BMI 23.3 ± 3.4) | Free living | Exclusion criteria: diabetes, smoking, dieting, athletes in training, abnormal blood cholesterol or blood pressure values, medication other than oral contraceptives, pregnant or lactating females | 3 vs 8 | Eucaloric—not reported how calculated | Balanced |
Hagele – 2018 [45] | Crossover trial | 2 × 14 days | 26 | 24.7 ± 3.2 | Both 13 women:13 men | Normal and overweight (BMI range 19.1—33.3 kg/m2) | Free living | Exclusion criteria: daily consumption of fruit juice or sugar-sweetened beverages outside of the trial, fructose intolerance, habitual meal skipping, chronic diseases, regular use of medication or supplements, alternative eating habits, or smoking | 3 vs 6 | Unclear—orange juice consumption was calibrated to 20% of daily energy requirements but 3 meals in both groups were uncontrolled | Unclear |
Grangiero – 2021 [46] | Parallel trial | 90 days | 47 | 29.1 ± 9.2 | Female | Class I&II obese (BMI between 30–39.9) | Free living | Exclusion criteria: smokers, menopausal age, not dieting or had a recent change in weight-status, history of bariatric surgery, athletes, medication or supplements for weight control, acute or chronic kidney disease, dyslipidemia, illiteracy, severe food compulsion measured via the Binge Eating Scale | 3 vs 6 | Eucaloric based on individualized measurements to attain -700 kcal balance | Deficit |