November 03, 2016
2 min read

Diet plus physical activity increases fitness

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NEW ORLEANS — Adding physical activity to diets does not induce additional weight loss compared with diet alone, according to a presenter here.

“We wanted to examine whether the public health recommendation of 150 minutes a week of physical activity or the widely accepted 200 to 250 minutes of moderate to vigorous physical activity affects health outcomes in terms of physical activity, weight loss and fitness compared to a group that had the same diet program but did not have a prescription for physical activity,” John M. Jakicic, PhD, chairperson of the department of health and physical activity, the Physical Activity and Weight Management Research Center at the University of Pittsburgh, said during his presentation.

John Jakicic
John M. Jakicic

Jakicic and colleagues evaluated 383 adults (mean age, 44.7 years; mean BMI, 32.4 kg/m2) randomly assigned to a reduced calorie diet (DIET; n = 127), diet plus a moderate dose of physical activity (150 minutes per week; MOD-EX; n = 129) or diet plus a high dose of physical activity (250 minutes per week; HIGH-EX; n = 127). Researchers sought to determine whethter adding physical activity recommended for public health (150 minutes per week) or weight control (250 minutes per week) to a diet enhances weight loss, body composition or fitness over 12 months.

Weekly in-person intervention sessions were performed for months 1 to 6, and combined in-person and telephonic sessions were performed for months 7 to 12. At baseline and 6 and 12 months, physical activity, weight, BMI, body fat and fitness were assessed.

Physical activity was higher in the HIGH-EX group compared with the other two groups at 6 months (HIGH-EX, 238.3 minutes per week; MOD-EX, 173 minutes; DIET, 91.4 minutes) and 12 months (HIGH-EX, 232.1 minutes; MOD-EX, 181.1 minutes; DIET, 90.6 minutes).

No difference was found between the groups for weight loss at 6 months or 12 months.

“Physical activity did not add additional weight loss when looking at the completers of the study,” Jakicic said during his presentation.

Changes in body fat and BMI were similar across the groups.

“We think our weight-loss programs did a pretty good job of achieving the anticipated weight loss,” Jakicic said. “We had very few adverse events. However, the prescribed level of physical activity per group did not improve weight loss, which is different from what you see sometimes in shorter-term studies or when you look at secondary data. However, there is a dose effect on cardiorespiratory fitness so fitness is an important cardiovascular outcome that we need to pay attention too.” – by Amber Cox


Jakicic J, et al. ORAL T-OR-2015. Presented at: ObesityWeek 2016; Oct. 31-Nov. 4, 2016; New Orleans.

Disclosure: Jakicic reports various financial ties with Ethicon and Medtronic Minimally Invasive Therapies.