Background: Postprandial hypoglycemia (PPHG) is an underrecognized complication of gastric bypass in people with type 2 diabetes (T2D). Recurrent PPHG can hinder the appearance of warning symptoms and influence dietary habits. Therefore, we examined the impact of recurrent PPHG quantified by continuous glucose monitoring (CGM) on hypoglycemia awareness and dietary behaviors in free-living patients with history of T2D treated with gastric bypass. Methods: In this case-control study, 24 subjects with history of T2D treated with gastric bypass 1-4 years before enrollment (14 women, age 54±9 years, BMI 29.3±6.3 kg/m2, HbA1c 36±6 mmol/mol) underwent a 300min 75g OGTT for the diagnosis of PPHG (plasma glucose nadir <3.0 mmol/L or <3.3 mmol/L with symptoms). Hypoglycemia symptoms were assessed by the Edinburgh Hypoglycemia Symptoms Scale (EHSS). Hunger, fullness, desire to eat, and prospective food consumption were measured using visual analogue scales (VAS). Cognitive alterations indicative of neuroglycopenia were examined by the Sternberg working memory test and the four-choice reaction time test. Free-living glycemic control and dietary habits were assessed by 14-day CGM and quantitative self-reported food diaries. Results: During the OGTT, 12 of 24 (50%) subjects had PPHG. At glucose nadir, all participants experienced a mild increase in EHSS-defined symptoms, hunger and desire to eat, as well as a small reduction in the accuracy at the Sternberg test, without differences between the PPHG and control groups. Other measured variables were not affected by the OGTT. In free-living conditions, PPHG subjects spent on average 9% more time below the range of glucose normality and experienced 1.3 more daily hypoglycemic events compared with controls. Energy and macronutrient composition of the diet, including daily carbohydrate and sugar intake, were similar between groups. However, PPHG subjects consumed on average 1.6 more meals/snacks each day, over a numerically 48-min longer eating window (p=0.057), compared with controls. Conclusions: Recurrent PPHG after gastric bypass is frequently experienced in patients with history of T2D, leading to hypoglycemia unawareness and maladaptive changes in dietary habits. These findings support an active screening for post-bypass PPHG even in asymptomatic patients for its potential negative health consequences.