Role of Dietary Habits in Efficacy of Bariatric Surgery - Study C

The obesity epidemic is a major public health concern with a significant economic burden in
the USA. Bariatric surgery is the most effective and durable weight loss treatment, with
long-term cardiometabolic health benefits. Among different types of bariatric procedures,
sleeve gastrectomy (SG) has become the most commonly performed in USA. While SG is expected
to result in a 50-60% excess weight loss, inter-individual differences in weight loss are
large and approximately 25% of patients can be considered poor weight-loss responders who
either do not lose a substantial amount of weight or regain the lost weight afterwards. The
mechanisms underlying this clinical variation remain unknown and interventions to improve on
these outcomes critically lacking. Of interest, altered daily dietary habits are experienced
by a substantial proportion of bariatric surgery candidates, raising the question whether
such alterations may contribute to inter-individual differences in weight loss success.
Therefore, the purpose of the study is to test how dietary habit interventions affect
patients with poor weight loss outcomes after bariatric surgery. Since this is a single blind
study, the details of the dietary interventions cannot be released during recruitment stage,
but will be made public once enrollment closes.

Inclusion Criteria:

- Bariatric surgery (sleeve gastrectomy) patients

- Pre-surgery BMI of 35-55 kg/m^2

Exclusion Criteria:

- Diabetes

- Anemia

- Smoking

- Use of more than 1 anti-hypertensive drug or beta-blockers

- Shift work within the past 1 year

- History of psychiatric illnesses or psychiatric disorders

- Obstructive sleep apnea or prescribed continuous positive air pressure

- Drug or alcohol dependency