Physical and Cognitive Function - Look AHEAD Ancillary Study

Obesity is associated with physical disability through both direct pathways (e.g., lower
extremity pain, insufficient muscle strength) and indirect pathways (obesity-related
comorbidities and inflammation). Furthermore, diabetes, a major obesity-related health
condition, is associated with increased risk of disability and accelerated declines in
physical and cognitive function. The investigators preliminary data suggest that intentional
weight loss improves physical function, and there is strong circumstantial evidence that it
would also benefit cognitive function.

To evaluate the role of intentional weight loss on physical and cognitive function, the
investigators propose an ancillary study to the on-going Look AHEAD (Action for Health in
Diabetes) trial. Look AHEAD is a multi-center, randomized clinical trial to examine the
effects of a 4-year lifestyle intervention designed to achieve and maintain weight loss
through decreased caloric intake and exercise in overweight or obese men and women aged 45-74
years with type 2 diabetes. The investigators propose to add validated and well-established
measures of physical and cognitive performance to the year 8 follow-up visit - during the
trial's weight maintenance phase - in ~1000 participants at 4 of the 16 Look AHEAD field
sites (Colorado, Memphis, Pennington and Pittsburgh).

The specific aims of this ancillary study are: 1) To determine the long-term effects of a
lifestyle intervention designed to achieve and maintain weight loss on physical function; and
2) To determine the long-term effects of a lifestyle intervention designed to achieve and
maintain weight loss on cognitive function. In addition, the investigators hypothesize that
in the intervention group, larger initial weight loss, better weight loss maintenance, and
higher physical activity will be associated with better physical and cognitive function. The
investigators also hypothesize that in the control group weight loss will be associated with
worse physical and cognitive function than in those who are weight stable or who have gained
weight.

The number of obese older adults is rising rapidly and there are few data to guide an
evidence-based clinical response to their management. The results of this study will provide
the first direct evidence of the role of long-term intentional weight loss on the maintenance
of physical and cognitive function in older obese adults with diabetes. Since this study is
being done as an ancillary study to an on-going trial it can be done in a timely and
cost-efficient manner.