Table 3.

Summary table of studies of MMT in PBH.

Study	Population	Type of MMT when the test was done	Definition of hypoglycaemia	Prevalence of hypoglycaemia
Gasser, 2019 (42)	RYGB, n = 113, symptoms not stated	Carbohydrate rich MMT (201 kcal) Low-carbohydrate MMT (195 kcal) in PBH subset (n = 13) At 12 months post-op, 150 min	<54 mg/dL (3.0 mmol/L)	13.2% of RYGB with carbohydrate-rich MMT; none identified with PBH had hypo with low-carbohydrate MMT
Roslin, 2014 (31)	RYGB, n = 12 VSG, n = 12 DS, n = 12 Symptoms not stated	Mixed-meal in form of muffin containing 100 g glucose, post-op interval 9 months, 120 min	Not stated	Average 2 h glucose for RYGB= 85.3 ± 41 mg/dL (4.7 ± 2.3 mmol/L); VSG = 89.3 ± 39 mg/dL (5 ± 2.2 mmol/L); DS = 83.3 ± 23 mg/dL (4.6 ± 1.3 mmol/L)
Faro, 2018 (43)	Symptomatic RYGB, n = 5	MMT stimulus: 500 kcal, 20% protein, 20% fat and 60% carbohydrates), post-op interval 1.5–10 years, 120 min	Not stated	Nadir glucoses at 120 min of 45; 34; 52; 26; 43 mg/dL (respectively 2.5; 1.9; 2.9; 1.4; 2.4 mmol/L)
Goldfine, 2007 (9)	Symptomatic RYGB, n = 12 Asymptomatic RYGB, n = 9 Non-RYGB similar BMI pre-op, n = 5 Non RYGB similar BMI post-op, n = 10	Ensure, 9 g protein, 40 g carbohydrates, 6 g fat, 240 mL, post-op interval 0.8–3.8 in symptomatic group, 2–4 years in asymptomatic group, 120 min	<60 mg/dL (<3.33 mmol/L)	3/9 asymptomatic people developed asymptomatic hypoglycaemia
Honka, 2019 (44)	Symptomatic RYGB, n = 43 Asymptomatic RYGB, n = 52 Separate cohort Symptomatic RYGB, n = 31 Asymptomatic RYGB, n = 18	350 kcal MTT (Ensure Plus®, 51 g carbohydrates) Isovolemic 250 kcal liquid MTT (Ensure®, 40 g carbohydrates) post-op interval not stated Sampling duration not stated	Not stated	A nadir blood glucose cut-off of 53 mg/dL (2.9 mmol/L) produced the highest sum of sensitivity (65%) and specificity (88%) for detecting hypoglycaemia
Jacobsen, 2012 (45)	Eight people pre and 2 weeks after RYGB	200 mL liquid mixed meal test (Nutridrink, Nutricia, Netherlands) containing 300 kcal (1260 kJ) with 49% carbohydrate, 35% fat and 16% protein. Also compared to 25 and 50 g OGTT, 210 min	Not stated	No change pre- and post-operatively
Kefurt, 2015 (46)	Symptoms not stated, RYGB, n = 51	200 mL liquid (all in® COMPLETE Kaffee, Allin, Vienna) containing 7.2 g fat, 28.4 g carbohydrates and 16 g protein, post-op interval mean 7.2 years, 180 min	<55 mg/dL (3.1 mmol/L)	29%
Lee, 2022 (47)	Symptomatic SG, n = 12 Asymptomatic SG, n = 11 Symptomatic RYGB, n = 7 Asymptomatic RYGB, n = 13	8-ounce Ensure Plus drink (Abbott Laboratories; 350 kcal, 50 g carbohydrates, 13 g protein, and 11 g fat), post-op interval average 5 years, 240 min	<60 mg/dL (3.3 mmol/L)	SG 39%, RYGB 40%
Lobato, 2020 (12)	Symptomatic RYGB, n = 14 Asymptomatic RYGB, n = 9	Liquid Mixed Meal (Fresubin Energy Drink, 200 mL, 300 kcal (50E% carbohydrate, 15E% protein and 35E% fat); Fresenius Kabi Deutschland, Bad Homburg, Germany), post-op interval ~3–5 years, 120 min	<55 mg/dL (3.1 mmol/L)	50% symptomatic, 44.4% asymptomatic
Mulla, 2019 (15)	Symptomatic RYGB, n = 11 Asymptomatic RYGB, n = 7 Overweight non operated, n = 3 Obesity non operated, n = 4	(Ensure, 40 g carbohydrates, 9 g protein, 6 g fat, 240 mL; Abbott Laboratories, Abbott Park, IL) Post-op interval not stated, 120 min	Not defined	Nadir glucose (mmol/L) (RYGB symptomatic: 4.3 ± 0.2; RYGB asymptomatic: 3.9 ± 0.1; Overweight non operated: 5.5 ± 0.2; Obesity non operated: 5.3 ± 0.3
Patti, 2015 (48)	Symptomatic RYGB, n = 17 Asymptomatic RYGB, n = 6	(Ensure, 40 g carbohydrates, 9 g protein, 6 g fat, 240 mL) post-op interval ~3–5 years, 120 min	<60 mg/dL (3.33 mmol/L)	Hypos detected in 7/17 (41%) of the symptomatic group 0/9 of the asymptomatic group had hypos
Preskill, 2015 (49)	Symptomatic RYGB, n = 31 Asymptomatic RYGB, n = not reported	MMT containing carbohydrate, fat, and protein (in solid form), post-op interval not reported, 300 min	<55 mg/dL (<3.1 mmol/L)	2/31 of the symptomatic group Asymptomatic not reported
Raverdy, 2017 (50)	RYGB, n = 89 AGB, n = 20 Unselected prospective cohort study	MMT not specified, pre-surgery, 12 and 60 months post surgery, 180 min	Not specified	2 h post-prandial lower after RYGB than AGB
Salehi, 2010 (51)	Symptomatic RYGB, n = 20 with CBG <50 mg/dL Asymptomatic RYGB, n = 21	MMT 350 kcal not specified, post-op interval and sampling duration not reported	Not specified	Nadir glucose <50 mg/dL (<2.8 mmol/L) in 9/20 symptomatic and 5/21 asymptomatic
Smajis, 2016 (52)	Symptomatic RYGB (GB), n = 10 Symptomatic of hypoglycaemia but with no surgery (CON), n = 5	Solid MMT (one meal consisting of 40 g whole wheat bread, 15 g butter, 20 g honey and 100 g banana (total kcal: 360; 4 g protein, 13 g fat, 57 g carbohydrate), post-op interval not reported, 240 min	<55 mg/dL (3.1 mmol/L)	Asymptomatic hypoglycaemia detected in GB = 2/10 and CON = 2/5
Emous, 2019 (53)	RYGB, n = 44	200 mL liquid nutrition supplement (Abbott Ensure S Plus) containing 300 kcal, 12.5 g protein, 40.4 g carbohydrate (of which 13.8 g is sugars), 9.84 g fat and 154.9 g water MMT, 4 years post-op, 210 min	<60 mg/dL (3.3 mmol/L)	Hypos in 48%, all asymptomatic
Tharakan, 2017 (54)	Symptomatic RYGB, n = 18 Asymptomatic RYGB, n = 10 non-RYGB controls, n = 9	Ensure Plus food supplement (13.8 g of protein, 10.8 g of fat, 44.4 g of carbohydrates, 330 kcal, 220 mL, Abbott)	<3.0 mmol/Ll	Hypos in 7/18 symptomatic people
Johannson, 2010 (55)	BPD-DS, n = 10 Normal weight controls, n = 12	Mixed meal including hamburger, and jam sandwich with margarine and oat bread, 2400 kJ (570 kcal), consisting of: carbohydrates 68.2 g, fat 22.3 g, proteins 24.6 g and fibre 6.4 g. 2 years post-op, 180 min	Not prespecified	No reported hypoglycaemia

BPD-DS, biliopancreatic diversion with duodenal switch; DS, duodenal switch; (L)AGB, (laparoscopic) adjustable gastric banding; MMT, mixed meal test; RYGB, Roux-en-Y gastric bypass; SG, sleeve gastrectomy; VSG, vertical sleeve gastrectomy.