<b>Objective:
</b>Weight
loss achieved with very low-calorie diets (VLCD) can produce remission of Type
2 diabetes (T2D), but weight regain very often occurs with reintroduction of
higher calorie intakes. In contrast, bariatric surgery produces clinically
significant and durable weight loss, with diabetes remission that translates
into reductions in mortality. We hypothesised that in patients living with
obesity and pre-diabetes/T2D, longitudinal changes in brain activity in
response to food cues as measured using functional MRI would explain this
difference. <b>Methods:</b> 16 participants underwent gastric bypass surgery
and 19 matched participants undertook a very low calorie (meal replacement)
diet for 4 weeks. Brain responses to food cues and resting state functional
connectivity was assessed with functional MRI pre- and post-intervention and
compared across groups. <b>Results:</b> We show that RYGB results in three
divergent brain responses in comparison to VLCD-induced weight loss: (i) VLCD
resulted in increased brain reward centre food cue responsiveness whereas in
RYGB this was reduced; (ii) VLCD resulted in higher neural activation of
cognitive control regions in response to food cues, associated with exercising
increased cognitive restraint over eating, whereas RYGB did not; (iii) a
homeostatic appetitive system (centred on the hypothalamus) is better engaged
following RYGB-induced weight loss than VLCD. <b>Conclusion:</b> Taken together
these findings point to divergent brain responses to different methods of
weight loss in patients with diabetes, which may explain weight regain after a
short-term VLCD in contrast with the enduring weight loss after RYGB.
The Mitigating Effect of Phentermine and Topiramate on Weight Regain After Roux‐en‐Y Gastric Bypass Surgery