Diet coaching curbs weight gain in women at GDM risk

BOSTON – Women at risk for gestational diabetes held off excess weight gain better when coached on healthy eating alone compared with those coached about physical activity, or on diet and exercise together.

The findings, presented at the annual scientific sessions of the American Diabetes Association, come from a pilot study in 150 obese pregnant women recruited from nine European countries randomized to one of the three lifestyle interventions.

The pilot study is the precursor to a larger ongoing randomized trial called DALI (Vitamin D & Lifestyle Intervention for Gestational Diabetes Mellitus Prevention). Dr. David Simmons of the University of Western Sydney, Australia, who presented the pilot study’s findings at the meeting, said he and his coinvestigators found it puzzling that a combined diet-and-exercise intervention would be less effective than a diet-alone intervention.

The women, all recruited at or before week 19 of their pregnancies (most entered around week 14), were well matched across the study arms for body mass index (mean 34.1-34.8) and fasting glucose and insulin sensitivity measurements at baseline. A glucose tolerance test was used to exclude women with GDM at baseline, though some of the women in the cohort had previous GDM. Also excluded were women unable to comply with the recommendations because of physical or psychiatric disability.

The researchers created five sets of recommendations for physical activity (for example: sitting less, building strength, taking more steps) and another seven for eating (including increasing intake of protein, vegetables, and fiber, and reducing intake of carbohydrates and fat) that were emphasized and detailed by lifestyle coaches during the intervention. The intervention was delivered over five in-person, one-on-one coaching sessions 30-45 minutes long, with follow-up phone calls in between. The sessions lasted through week 30.

Women in the combined group received all 12 of the diet and exercise messages. The problem may have been an overload of guidance in that arm of the study, Dr. Simmons said.

“We thought it was a no-brainer that the more you put in, the more you’d get out,” he said. But possibly, “having 12 messages kind of swamped people, and it was just too much for them to focus on.”

Women randomized to physical activity counseling alone (n = 50) saw 2.6 kilograms more weight gain at 24-28 weeks of pregnancy than did women randomized to nutrition counseling alone (n = 50), Dr. Simmons reported. The difference narrowed to 1.6 kilos by 35-37 weeks but remained significant.

Fasting glucose measurements were significantly higher in the exercise group at 35-37 weeks compared with the nutrition group. The combined intervention was not significantly better than was exercise alone for either the fasting glucose or weight measures. Though the study was not powered to detect significant differences in GDM risk, women in the physical activity group saw a higher incidence of GDM, 42%, compared to 31% for the combined intervention and 28% for the diet-only group.

The findings suggest “that healthy eating was the more efficacious strategy in dealing with excess weight gain,” which is a risk factor for GDM, said Dr. Simmons. “What we see now certainly justifies the use of early healthy eating interventions in obese pregnant women.”

He added that the larger trial, which will randomize 440 women with the same characteristics to one of the three lifestyle interventions or no intervention, will seek to confirm the findings and will be powered to pick up significant differences in GDM risk.

A separate trial under DALI, recruiting another 440 obese pregnant women, will look at vitamin D supplementation alone and alongside lifestyle inventions, and placebo.

The DALI studies are funded by the European Commission. Dr. Simmons declared no conflict of interest.

BOSTON – Women at risk for gestational diabetes held off excess weight gain better when coached on healthy eating alone compared with those coached about physical activity, or on diet and exercise together.

The findings, presented at the annual scientific sessions of the American Diabetes Association, come from a pilot study in 150 obese pregnant women recruited from nine European countries randomized to one of the three lifestyle interventions.

The pilot study is the precursor to a larger ongoing randomized trial called DALI (Vitamin D & Lifestyle Intervention for Gestational Diabetes Mellitus Prevention). Dr. David Simmons of the University of Western Sydney, Australia, who presented the pilot study’s findings at the meeting, said he and his coinvestigators found it puzzling that a combined diet-and-exercise intervention would be less effective than a diet-alone intervention.

The women, all recruited at or before week 19 of their pregnancies (most entered around week 14), were well matched across the study arms for body mass index (mean 34.1-34.8) and fasting glucose and insulin sensitivity measurements at baseline. A glucose tolerance test was used to exclude women with GDM at baseline, though some of the women in the cohort had previous GDM. Also excluded were women unable to comply with the recommendations because of physical or psychiatric disability.

The researchers created five sets of recommendations for physical activity (for example: sitting less, building strength, taking more steps) and another seven for eating (including increasing intake of protein, vegetables, and fiber, and reducing intake of carbohydrates and fat) that were emphasized and detailed by lifestyle coaches during the intervention. The intervention was delivered over five in-person, one-on-one coaching sessions 30-45 minutes long, with follow-up phone calls in between. The sessions lasted through week 30.

Women in the combined group received all 12 of the diet and exercise messages. The problem may have been an overload of guidance in that arm of the study, Dr. Simmons said.

“We thought it was a no-brainer that the more you put in, the more you’d get out,” he said. But possibly, “having 12 messages kind of swamped people, and it was just too much for them to focus on.”

Women randomized to physical activity counseling alone (n = 50) saw 2.6 kilograms more weight gain at 24-28 weeks of pregnancy than did women randomized to nutrition counseling alone (n = 50), Dr. Simmons reported. The difference narrowed to 1.6 kilos by 35-37 weeks but remained significant.

Fasting glucose measurements were significantly higher in the exercise group at 35-37 weeks compared with the nutrition group. The combined intervention was not significantly better than was exercise alone for either the fasting glucose or weight measures. Though the study was not powered to detect significant differences in GDM risk, women in the physical activity group saw a higher incidence of GDM, 42%, compared to 31% for the combined intervention and 28% for the diet-only group.

The findings suggest “that healthy eating was the more efficacious strategy in dealing with excess weight gain,” which is a risk factor for GDM, said Dr. Simmons. “What we see now certainly justifies the use of early healthy eating interventions in obese pregnant women.”

He added that the larger trial, which will randomize 440 women with the same characteristics to one of the three lifestyle interventions or no intervention, will seek to confirm the findings and will be powered to pick up significant differences in GDM risk.

A separate trial under DALI, recruiting another 440 obese pregnant women, will look at vitamin D supplementation alone and alongside lifestyle inventions, and placebo.

The DALI studies are funded by the European Commission. Dr. Simmons declared no conflict of interest.

BOSTON – Women at risk for gestational diabetes held off excess weight gain better when coached on healthy eating alone compared with those coached about physical activity, or on diet and exercise together.

The findings, presented at the annual scientific sessions of the American Diabetes Association, come from a pilot study in 150 obese pregnant women recruited from nine European countries randomized to one of the three lifestyle interventions.

The pilot study is the precursor to a larger ongoing randomized trial called DALI (Vitamin D & Lifestyle Intervention for Gestational Diabetes Mellitus Prevention). Dr. David Simmons of the University of Western Sydney, Australia, who presented the pilot study’s findings at the meeting, said he and his coinvestigators found it puzzling that a combined diet-and-exercise intervention would be less effective than a diet-alone intervention.

The women, all recruited at or before week 19 of their pregnancies (most entered around week 14), were well matched across the study arms for body mass index (mean 34.1-34.8) and fasting glucose and insulin sensitivity measurements at baseline. A glucose tolerance test was used to exclude women with GDM at baseline, though some of the women in the cohort had previous GDM. Also excluded were women unable to comply with the recommendations because of physical or psychiatric disability.

The researchers created five sets of recommendations for physical activity (for example: sitting less, building strength, taking more steps) and another seven for eating (including increasing intake of protein, vegetables, and fiber, and reducing intake of carbohydrates and fat) that were emphasized and detailed by lifestyle coaches during the intervention. The intervention was delivered over five in-person, one-on-one coaching sessions 30-45 minutes long, with follow-up phone calls in between. The sessions lasted through week 30.

Women in the combined group received all 12 of the diet and exercise messages. The problem may have been an overload of guidance in that arm of the study, Dr. Simmons said.

“We thought it was a no-brainer that the more you put in, the more you’d get out,” he said. But possibly, “having 12 messages kind of swamped people, and it was just too much for them to focus on.”

Women randomized to physical activity counseling alone (n = 50) saw 2.6 kilograms more weight gain at 24-28 weeks of pregnancy than did women randomized to nutrition counseling alone (n = 50), Dr. Simmons reported. The difference narrowed to 1.6 kilos by 35-37 weeks but remained significant.

Fasting glucose measurements were significantly higher in the exercise group at 35-37 weeks compared with the nutrition group. The combined intervention was not significantly better than was exercise alone for either the fasting glucose or weight measures. Though the study was not powered to detect significant differences in GDM risk, women in the physical activity group saw a higher incidence of GDM, 42%, compared to 31% for the combined intervention and 28% for the diet-only group.

The findings suggest “that healthy eating was the more efficacious strategy in dealing with excess weight gain,” which is a risk factor for GDM, said Dr. Simmons. “What we see now certainly justifies the use of early healthy eating interventions in obese pregnant women.”

He added that the larger trial, which will randomize 440 women with the same characteristics to one of the three lifestyle interventions or no intervention, will seek to confirm the findings and will be powered to pick up significant differences in GDM risk.

A separate trial under DALI, recruiting another 440 obese pregnant women, will look at vitamin D supplementation alone and alongside lifestyle inventions, and placebo.

The DALI studies are funded by the European Commission. Dr. Simmons declared no conflict of interest.