Table 2.

Key outcome measures and covariates.

Authors	Control Group	Method of Dietary Monitoring	Dietary Outcome Measures	Results	Conclusions/Recommendations
Dias et al. (2009) [42]	No	Unclear–“energy and protein ingestion transcribed from patient’s chart” (Trimester 2 and 3).	Energy intake Protein intake	Trimester 2 mean daily intake: Energy: 1789 ± 659 kcal Protein: 61.7 ± 19.8 g Trimester 3 mean daily intake: Energy: 1881 ± 835 kcal Protein: 62.8 ± 19.2 g	Energy, but not protein intake during pregnancy was appropriate. Long term nutritional monitoring should be a priority and dietary recommendations are in clear demand.
Guelinckx et al. (2012) [45]	No	7 day food diary (Trimester 1 and 2)	Energy intake Protein as % energy Total fat as % energy Saturated fat as % energy Carbohydrate as % energy Fibre Calcium Iron Diet quality (HEI score)	Trimester 1 mean daily intake LAGB participants: Energy: 1971 ± 430 kcal Protein as % energy: 15.1 ± 1.5 Total fat as % energy: 35.3 ± 4.7 Saturated fat as % energy: 13.0 ± 2.6 Carbohydrate as % energy: 49.8 ± 5.4 Fibre: 19.5 ± 5.4 g Calcium: 822 ± 273 mg Iron: 11 ± 2 mg RYGB participants: Energy: 1786 ± 283 kcal Protein as % energy: 15.8 ± 2.1 Total fat as % energy: 35.9 ± 3.3 Saturated fat as % energy: 14.2 ± 2.3 Carbohydrate as % energy: 48.5 ± 3.9 Fibre: 17.5 ± 5.3 g Calcium: 702 ± 228 mg Iron: 9 ± 2 mg Trimester 2 mean daily intake LAGB participants: Energy: 1978 ± 472 kcal Protein as % energy: 15.5 ± 2.2 Carbohydrate as % energy: 49.4 ± 4.4 Total fat as % energy: 14.2 ± 2.3 Saturated fat as % energy: 13.6 ± 2.4 Fibre: 17.7 ± 5.8 g Calcium: 806 ± 384 mg Iron: 10 ± 2 mg RYGB participants: Energy: 1895 ± 542 kcal Protein as % energy: 15.1 ± 2.4 Total fat as % energy: 35.1 ± 4.0 Saturated fat as % energy: 14.2 ± 1.9 Carbohydrate as % energy: 49.9 ± 4.4 Fibre: 18.2 ± 3.5 g Calcium: 764 ± 370 mg Iron: 10 ± 30 mg	Mean daily intake of fat and saturated fat and protein higher than recommended levels. Carbohydrate intake lower than recommended. Fibre and calcium lower than recommended. Iron intake sufficient. HEI score did not change during pregnancy and was comparable between groups. During the first trimester, 15% of participants had a healthy diet, 82% required improvement and 3% had a poor quality diet. In the second trimester, 10% had a healthy diet and 90% required improvement. Nutritional advice and lifestyle coaching recommended for this high-risk population.
Jans et al. (2018) [43]	Yes 25 pregnant women with obesity	3 day food record (Trimester 1 and 3)	Energy intake Total fat intake Saturated fat intake MUFA intake PUFA intake n3 fatty acids n6 fatty acids Folate Vitamin B12	Trimester 1 mean daily intake: Energy: 1452.46 ± 415.99 kcal Total fat: 56.21 ± 19.65 g Saturated fat: 23.39 ± 8.81 g MUFA: 17.73 ± 7.00 g PUFA: 8.80 ± 3.75 g n3 fatty acids: 0.78 (0.12–2.06) * g n6 fatty acids: 5.42 (1.38–15.25) * g Folate: 177.25 (42.01–419.62) * mcg Vitamin B12: 2.94 (0.59–8.54) * mcg Trimester 3 mean daily intake: Energy: 1514.47 ± 503.69 kcal Total fat: 56.8 ± 20.50 g Saturated fat: 24.25 ± 9.33 g MUFA: 17.86 ± 7.39 g PUFA: 8.35 (2.86–24.34) * g n3 fatty acids: 0.64 (0.12–2.28) * g n6 fatty acids: 5.18 (1.16–19.76) * g Folate: 171.75 ± 68.04 mcg Vitamin B12: 2.92 ±1.29 mcg	Both surgical and obese groups consumed a diet high in saturated fatty acids and low in unsaturated fatty acids. Intakes of n3 fatty acids, folate and vitamin B12 were below Belgian dietary recommendations. Pregnancy following bariatric surgery induces high levels of anxiety that are not associated with an inadequate maternal diet.
Coupaye (2018) [44]	No	4 day self-reported food diary (Trimester 2)	Energy intake Protein intake Carbohydrate intake Fat intake	Mean daily intake: RYGB participants: Energy intake: 1385 ± 400 kcal Protein intake: 59.1 ± 20.9 g Carbohydrate: 164 ± 49 g Fat: 54.8 ± 19.1 g SG participants: Energy: 1222 ± 425 kcal Protein: 46.7 ± 14.5 g Carbohydrate: 152 ± 59 g Fat: 47.3 ± 20.3 g	Energy, carbohydrate and fat intake did not differ between those who had RYGB and SG. Protein intake was significantly higher in those who had RYGB, but still below the 60 g/day recommendation. Fetal growth after bariatric surgery is positively associated with maternal protein supply and negatively correlated with maternal iron status.

Values are mean ± standard deviation unless stated. * median values with interquartile range in brackets. HEI: Healthy Eating Index MUFA: Monounsaturated fatty acids. PUFA: Polyunsaturated fatty acids RYGB: Roux en Y Gastroplasty SG: Sleeve Gastrectomy.