Ignite Creation Date:
2024-05-05 @ 11:26 PM
Last Modification Date:
2024-10-26 @ 10:34 AM
Study NCT ID:
NCT01337895
Status:
WITHDRAWN
Last Update Posted:
2011-11-11
First Post:
2011-04-15
Brief Title:
DAWL Dairy and Weight Loss Study
Sponsor:
University of Guelph
Organization:
University of Guelph
Study Overview
Official Title:
Diet and Weight Loss Study - a Weight Loss Trial to Determine Whether Dairy Products Augment Weight Loss for Adults Following an Energy-restricted Weight Loss Study
Status:
WITHDRAWN
Status Verified Date:
2011-08
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Grant not funded study will not launch
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
DAWL
Brief Summary:
Objectives Taking a whole foods approach we will investigate i whether consumption of isocaloric diets containing 4 vs 1 servings of dairy products per day for 16 weeks results in greater body fat loss in energy-restricted overweightobese premenopausal women ii the role of dairy product consumption in influencing physiological and metabolic factors which may precede or accompany changes in body composition including in enzymes which synthesize and break down body fat and iii factors including obesity phenotype which may influence the response of body composition to dairy product consumption
Background
With the obesity epidemic showing no signs of abating there is ongoing interest both at the lay public and scientific levels in manipulating the diet to promote weight specifically fat loss One such promising manipulation is an increase in or perhaps more precisely an isocaloric substitution of dairy product consumption The inverse association between Body Mass Index BMI and dietary calcium - for which dairy products are the main source - was first described in 1984 and has since been supported by various levels of evidence but not consistently Heaney recently described this literature as confused which he and Rafferty attribute to important limitations in study design including lack of low-calcium contrast groups and the fact that body weightbody composition is often a secondary endpoint in studies designed and powered for a different outcome typically bone health or blood pressure Confusion has also arisen from the investigation of different interventions dairy products dairy calcium dietary calcium supplemental calcium making it difficult to compare and interpret studies This creates an opportunity for the proposed Dairy and Weight Loss DAWL study with its focus on whole dairy product consumption to help clear up the confusion surrounding this issue
Hypotheses
Overweightobese low habitual dairy consuming premenopausal women randomized to an energy-restricted weight loss diet containing 4 servingsday of dairy products milk yogurt cheese for 16 weeks will lose more body fat than those randomized to an isocaloric diet containing 1 servingsday of dairy products
Background
With the obesity epidemic showing no signs of abating there is ongoing interest both at the lay public and scientific levels in manipulating the diet to promote weight specifically fat loss One such promising manipulation is an increase in or perhaps more precisely an isocaloric substitution of dairy product consumption The inverse association between Body Mass Index BMI and dietary calcium - for which dairy products are the main source - was first described in 1984 and has since been supported by various levels of evidence but not consistently Heaney recently described this literature as confused which he and Rafferty attribute to important limitations in study design including lack of low-calcium contrast groups and the fact that body weightbody composition is often a secondary endpoint in studies designed and powered for a different outcome typically bone health or blood pressure Confusion has also arisen from the investigation of different interventions dairy products dairy calcium dietary calcium supplemental calcium making it difficult to compare and interpret studies This creates an opportunity for the proposed Dairy and Weight Loss DAWL study with its focus on whole dairy product consumption to help clear up the confusion surrounding this issue
Hypotheses
Overweightobese low habitual dairy consuming premenopausal women randomized to an energy-restricted weight loss diet containing 4 servingsday of dairy products milk yogurt cheese for 16 weeks will lose more body fat than those randomized to an isocaloric diet containing 1 servingsday of dairy products
Detailed Description:
Ground zero for the DAWL study will be the University of Guelph Body Composition and Metabolism Lab wwwuoguelphcabodycomp under the direction of the PI
Sample Size The investigators plan to complete data collection on a total of 46 women This sample size is based on an anticipated total body fat mass FM loss over 16 weeks of 55 kg in the high dairy group and 38 kg in the control group These values are based on data published from 4 studies 5 20-22 To be conservative in our sample size calculation we used a higher-than-reported SD of 20 kg FM loss Together these values indicated that we require 23 women in each group to detect a significant difference in total body FM with 80 power and 5 alpha Attrition and non-adherence is anticipated to be approximately 20 to 25 therefore 30 women in each group will be recruited We anticipate screening approximately 300 women to collect 16 weeks of data on a total of 46 eligible and adherent completers as per Figure 1 below
InclusionExclusion Criteria Inclusion criteria include non-smoking non-pregnant and non-lactating women 18 to 50 years premenopausal determined by cessation of menstruation and recent menstrual history to exclude those who are perimenopausal or amennorheic BMI 250 kgm2 54 usual calcium consumption below the EAR of 800 mgd 55 to be measured using a validated calcium and vitamin D food frequency questionnaire FFQ 56 no sensitivity to dairy normal liver and kidney function serum calcium and complete blood count 3 mo history of weight stability and willingness to adhere to study protocol for 16 weeks regardless of treatment and including no change in physical activity levels Any vitaminmineral supplement users will be asked to discontinue supplementation for 4 weeks prior to enrolling in the trial ie wash out as well as for the duration of the trial
Exclusion criteria include violation of any of the above or presence of a health condition which might influence weight loss such as diabetes CVD cancer thyroid disease or regularly taking medication which may do the same such as corticosteroids
Comprehensive ScreeningBackground Data Collection Visit Women who pass the initial screen and attend the recruitment session will be invited back to the lab after having fasted for 12 hours no food or drink except water where they will first be asked to sign an informed consent form Further screeningbackground data to be collected will include
Biochemistry including complete blood count liver function tests ALT AST blood urea nitrogen creatinine and serum total calcium Participants will undergo venipuncture by a LifeLabs phlebotomist letter of support attached A 3 business day turnaround is anticipated for results Participants with values within normal limits will continue on to enrollment By this stage of recruitment participants with any known health conditionsmedications suspected to interfere with study outcomes will have been screened out therefore it is anticipated that most will have values within normal limits
International Physical Activity Questionnaire IPAQ 57 to assess usual activity habits
Resting metabolic rate kcald to determine the energy levels of individualized meal plans which will be calculated as RMR x PAL - 500 kcald RMR will be measured using continuous open-circuit indirect calorimetry using a MAX-IIa instrument AEI Technologies Inc RMR measurements will be conducted with participants lying awake but at complete physical rest with a ventilated hood placed over the head and neck Participants will undergo measurement for 30 to 40 minutes the first 5 to 10 minutes of data will be discarded to allow for acclimation to the testing environment We will provide a juice box and granola bar after this test so that participants are not hungry For consistency across study visits we will measure participants in the follicular phase of their menstrual cycles
145 Lead-In Phase During the two weeks following the comprehensive screening visit participants will be asked maintain a 3-day food record from which research personnel will create 500 kcal-restricted individualized meal plans as described below From this point on participants will be asked to maintain their usual physical activity levels
146 Study Diets Participants will be provided with individualized meal plans - high dairy or control - every two weeks for the duration of the study They will be counseled on their assigned diets by research personnel during the baseline visit and throughout the study The energy levels of the meal plans eg 1200 kcal 1400 kcal 1600 kcal etc will be determined from RMR and PAL levels as follows RMR x PAL - 500 kcald where RMR is resting metabolic rate kcald measured by indirect calorimetry PAL is physical activity level derived from the screening IPAQ and 500 kcal is the daily energy restriction The energy levels will be adjusted throughout the study as needed Actual foods in the meal plans will be based on Eating Well with Canadas Food Guide EWCFG httpwwwhc-scgccafn-anfood-guide-alimentindex-engphp and the 3-day food records completed during the lead-in phase The diets for the two treatment groups will be matched for energy and macronutrient protein fat carbohydrate intake as per the sample 1400 kcal meal plans attached and using ESHA Food Processor SQL version 1080 ESHA Research Salem OR updated with the 2010 Canadian Nutrient File
Dairy products for the high dairy group will be donated by Agropur Coopérative and Ultima Foods letter of support attached Consistent with EWCFG recommendations a variety of dairy products milk yogurt cheese will be included One serving will be considered 1 cup fluid white cows milk or chocolate milk 15 ounces cheese and 1 cup yogurt Although EWCFG considers 1 serving of yogurt to be 075 cups we will increase to 1 cup to provide equivalent calcium across all dairy products Minimum dairy calcium intake of the high-dairy group is anticipated to be 1200 mgd dietary calcium intake will be higher Dietary calcium of the control group is anticipated to be 450 mgd therefore we anticipate a spread of approximately 1000 mg dietary calcium per day between groups If energy levels of meal plans allow we will incorporate regular fat vs low fat dairy products to reflect Canadians actual dairy intake and maximize intake of CLA Participants in the high-dairy group will be provided with a 2 week supply of dairy products at a time in insulated transport bags
147 Baseline Visit week 0
Following lead-in participants will return to the lab for a baseline visit At this time participants will first be informed to which treatment they were randomly assigned by the biostatistician using a random number generator and to which they will be asked to adhere for 16 weeks We will divulge this prior to going any further to provide an opportunity for participants to withdraw Willing participants will then undergo a series of measurements
Weight as described above
Waist circumference will be measured twice on standing participants at the level of the iliac crest 58 using a Gulick II non-elastic tape measure if measures differ by 5 a third will be taken and the mean of the two closest values will be used Hip circumference will be measured twice on standing participants around the widest portion of the buttocks 59 if measures differ by 5 a third will be taken and the mean of the two closest values will be used Predominantly android obesity will be defined as a waist-to-hip ratio of 085 predominantly gynoid obesity will be defined as a waist-to-hip ratio of 085 59 60
Body composition Whole body and regional fat mass and lean mass will be measured by dual energy x-ray absorptiometry DXA using a fan beam Hologic Wi updated with APEX 32 software See Figure 2 Participants will be asked to wear underpants and a hospital gown only and to remove all metal jewelry for this test
Venipuncture A LifeLabs phlebotomist will draw fasting blood samples from each participant Biochemical analyses to be completed at LifeLabs include glucose insulin 25OHD lipids total cholesterol HDL LDL triglycerides high-sensitivity C-reactive protein hsCRP and parathyroid hormone PTH Various CLA isomers c9 t11 t10 c12 in red blood cells Dr David Ma and hepatic lipase lipoprotein lipase and mRNA expression of fatty acid synthase Dr Marica Bakovic will be analyzed in yearly batches at the University of Guelph Participants are required to fast for this visit we will provide a juice box and granola bar afterwards
Visual analog scale VAS to assess desire to eat hunger fullness and prospective food consumption 61 Scales are 100 mm in length and are anchored at either end with words expressing the most positive and negative ratings The VAS will be completed in the lab conference room after venipuncture
Sitting blood pressure using a digital blood pressure cuff Physio Logic model 106-94 Montréal PQ
148 Mid-Study Visit week 8 Participants will repeat the following tests weight waisthip circumferences DXA resting metabolic rate blood pressure
149 Study Conclusion week 16 Participants will repeat all of the same tests as during the Baseline Visit 1410 Adherence and Interim Visits Throughout the trial participants will maintain a daily dairy product intake checklist and weekly food and activity diaries to determine adherence to treatment group energy intake and physical activity Biweekly participants will visit the lab to turn in checklists have meal plans reassessed and have weight BMI and waisthip circumferences measured Those in the dairy group will pick up a 2 week supply of dairy products Participants will complete a monthly calcium and vitamin D FFQ 56
1411 Data Analysis Repeated measures ANOVA will be conducted for all measures collected at more than two time points to determine differences between treatment groups These include body composition DXA weight BMI waisthip circumferences dietary data physical activity resting metabolic rate visual analog scale and blood pressure Consistent with a prepost design paired t-tests will determine differences in biochemical variables measured at weeks 0 and 16 Regression analyses will be used to predict kilograms of fat mass lost with predictor variables including obesity phenotype predominantly android vs predominantly gynoid adjusted for any differences in BMI baseline 25OHD status age etc
1412 Knowledge Translation
Community provincial and national outreach to consumers Registered Dietitians RD other health care professionals and scientists will be achieved through multiple means
Gwen Laughton and Janine Robertson Guelph-based RD collaborators will provide KT assistance specifically tailored to the local context This includes presentations and discussion groups with other Guelph-based RDs to assist with health literacy for consumers and dissemination via the Waterloo Wellington Regional Nutrition Network We will also post the study on the web-based Ontario Nutrition Resource Centre an initiative of the Ontario Public Health Association
The DAWL study will be posted on the Canadian Inventory of Nutrition and Dietetic Associated Research CINDAR and Canadian Obesity Network CON websites and in the Members in Action section of the Dietitians of Canada newsletter The PI co-investigators and graduate students will collaborate on scientific publications and presentations at nutrition meetings eg Canadian Nutrition Society The research team will work with media specialists to reach and educate the public and with the agri-food chain industry not-for-profit trade association marketing group including Dairy Farmers of Canada Agropur Coopérative and Ultima Foods Dairy Farmers of Ontario Ontario Dairy Council
Sample Size The investigators plan to complete data collection on a total of 46 women This sample size is based on an anticipated total body fat mass FM loss over 16 weeks of 55 kg in the high dairy group and 38 kg in the control group These values are based on data published from 4 studies 5 20-22 To be conservative in our sample size calculation we used a higher-than-reported SD of 20 kg FM loss Together these values indicated that we require 23 women in each group to detect a significant difference in total body FM with 80 power and 5 alpha Attrition and non-adherence is anticipated to be approximately 20 to 25 therefore 30 women in each group will be recruited We anticipate screening approximately 300 women to collect 16 weeks of data on a total of 46 eligible and adherent completers as per Figure 1 below
InclusionExclusion Criteria Inclusion criteria include non-smoking non-pregnant and non-lactating women 18 to 50 years premenopausal determined by cessation of menstruation and recent menstrual history to exclude those who are perimenopausal or amennorheic BMI 250 kgm2 54 usual calcium consumption below the EAR of 800 mgd 55 to be measured using a validated calcium and vitamin D food frequency questionnaire FFQ 56 no sensitivity to dairy normal liver and kidney function serum calcium and complete blood count 3 mo history of weight stability and willingness to adhere to study protocol for 16 weeks regardless of treatment and including no change in physical activity levels Any vitaminmineral supplement users will be asked to discontinue supplementation for 4 weeks prior to enrolling in the trial ie wash out as well as for the duration of the trial
Exclusion criteria include violation of any of the above or presence of a health condition which might influence weight loss such as diabetes CVD cancer thyroid disease or regularly taking medication which may do the same such as corticosteroids
Comprehensive ScreeningBackground Data Collection Visit Women who pass the initial screen and attend the recruitment session will be invited back to the lab after having fasted for 12 hours no food or drink except water where they will first be asked to sign an informed consent form Further screeningbackground data to be collected will include
Biochemistry including complete blood count liver function tests ALT AST blood urea nitrogen creatinine and serum total calcium Participants will undergo venipuncture by a LifeLabs phlebotomist letter of support attached A 3 business day turnaround is anticipated for results Participants with values within normal limits will continue on to enrollment By this stage of recruitment participants with any known health conditionsmedications suspected to interfere with study outcomes will have been screened out therefore it is anticipated that most will have values within normal limits
International Physical Activity Questionnaire IPAQ 57 to assess usual activity habits
Resting metabolic rate kcald to determine the energy levels of individualized meal plans which will be calculated as RMR x PAL - 500 kcald RMR will be measured using continuous open-circuit indirect calorimetry using a MAX-IIa instrument AEI Technologies Inc RMR measurements will be conducted with participants lying awake but at complete physical rest with a ventilated hood placed over the head and neck Participants will undergo measurement for 30 to 40 minutes the first 5 to 10 minutes of data will be discarded to allow for acclimation to the testing environment We will provide a juice box and granola bar after this test so that participants are not hungry For consistency across study visits we will measure participants in the follicular phase of their menstrual cycles
145 Lead-In Phase During the two weeks following the comprehensive screening visit participants will be asked maintain a 3-day food record from which research personnel will create 500 kcal-restricted individualized meal plans as described below From this point on participants will be asked to maintain their usual physical activity levels
146 Study Diets Participants will be provided with individualized meal plans - high dairy or control - every two weeks for the duration of the study They will be counseled on their assigned diets by research personnel during the baseline visit and throughout the study The energy levels of the meal plans eg 1200 kcal 1400 kcal 1600 kcal etc will be determined from RMR and PAL levels as follows RMR x PAL - 500 kcald where RMR is resting metabolic rate kcald measured by indirect calorimetry PAL is physical activity level derived from the screening IPAQ and 500 kcal is the daily energy restriction The energy levels will be adjusted throughout the study as needed Actual foods in the meal plans will be based on Eating Well with Canadas Food Guide EWCFG httpwwwhc-scgccafn-anfood-guide-alimentindex-engphp and the 3-day food records completed during the lead-in phase The diets for the two treatment groups will be matched for energy and macronutrient protein fat carbohydrate intake as per the sample 1400 kcal meal plans attached and using ESHA Food Processor SQL version 1080 ESHA Research Salem OR updated with the 2010 Canadian Nutrient File
Dairy products for the high dairy group will be donated by Agropur Coopérative and Ultima Foods letter of support attached Consistent with EWCFG recommendations a variety of dairy products milk yogurt cheese will be included One serving will be considered 1 cup fluid white cows milk or chocolate milk 15 ounces cheese and 1 cup yogurt Although EWCFG considers 1 serving of yogurt to be 075 cups we will increase to 1 cup to provide equivalent calcium across all dairy products Minimum dairy calcium intake of the high-dairy group is anticipated to be 1200 mgd dietary calcium intake will be higher Dietary calcium of the control group is anticipated to be 450 mgd therefore we anticipate a spread of approximately 1000 mg dietary calcium per day between groups If energy levels of meal plans allow we will incorporate regular fat vs low fat dairy products to reflect Canadians actual dairy intake and maximize intake of CLA Participants in the high-dairy group will be provided with a 2 week supply of dairy products at a time in insulated transport bags
147 Baseline Visit week 0
Following lead-in participants will return to the lab for a baseline visit At this time participants will first be informed to which treatment they were randomly assigned by the biostatistician using a random number generator and to which they will be asked to adhere for 16 weeks We will divulge this prior to going any further to provide an opportunity for participants to withdraw Willing participants will then undergo a series of measurements
Weight as described above
Waist circumference will be measured twice on standing participants at the level of the iliac crest 58 using a Gulick II non-elastic tape measure if measures differ by 5 a third will be taken and the mean of the two closest values will be used Hip circumference will be measured twice on standing participants around the widest portion of the buttocks 59 if measures differ by 5 a third will be taken and the mean of the two closest values will be used Predominantly android obesity will be defined as a waist-to-hip ratio of 085 predominantly gynoid obesity will be defined as a waist-to-hip ratio of 085 59 60
Body composition Whole body and regional fat mass and lean mass will be measured by dual energy x-ray absorptiometry DXA using a fan beam Hologic Wi updated with APEX 32 software See Figure 2 Participants will be asked to wear underpants and a hospital gown only and to remove all metal jewelry for this test
Venipuncture A LifeLabs phlebotomist will draw fasting blood samples from each participant Biochemical analyses to be completed at LifeLabs include glucose insulin 25OHD lipids total cholesterol HDL LDL triglycerides high-sensitivity C-reactive protein hsCRP and parathyroid hormone PTH Various CLA isomers c9 t11 t10 c12 in red blood cells Dr David Ma and hepatic lipase lipoprotein lipase and mRNA expression of fatty acid synthase Dr Marica Bakovic will be analyzed in yearly batches at the University of Guelph Participants are required to fast for this visit we will provide a juice box and granola bar afterwards
Visual analog scale VAS to assess desire to eat hunger fullness and prospective food consumption 61 Scales are 100 mm in length and are anchored at either end with words expressing the most positive and negative ratings The VAS will be completed in the lab conference room after venipuncture
Sitting blood pressure using a digital blood pressure cuff Physio Logic model 106-94 Montréal PQ
148 Mid-Study Visit week 8 Participants will repeat the following tests weight waisthip circumferences DXA resting metabolic rate blood pressure
149 Study Conclusion week 16 Participants will repeat all of the same tests as during the Baseline Visit 1410 Adherence and Interim Visits Throughout the trial participants will maintain a daily dairy product intake checklist and weekly food and activity diaries to determine adherence to treatment group energy intake and physical activity Biweekly participants will visit the lab to turn in checklists have meal plans reassessed and have weight BMI and waisthip circumferences measured Those in the dairy group will pick up a 2 week supply of dairy products Participants will complete a monthly calcium and vitamin D FFQ 56
1411 Data Analysis Repeated measures ANOVA will be conducted for all measures collected at more than two time points to determine differences between treatment groups These include body composition DXA weight BMI waisthip circumferences dietary data physical activity resting metabolic rate visual analog scale and blood pressure Consistent with a prepost design paired t-tests will determine differences in biochemical variables measured at weeks 0 and 16 Regression analyses will be used to predict kilograms of fat mass lost with predictor variables including obesity phenotype predominantly android vs predominantly gynoid adjusted for any differences in BMI baseline 25OHD status age etc
1412 Knowledge Translation
Community provincial and national outreach to consumers Registered Dietitians RD other health care professionals and scientists will be achieved through multiple means
Gwen Laughton and Janine Robertson Guelph-based RD collaborators will provide KT assistance specifically tailored to the local context This includes presentations and discussion groups with other Guelph-based RDs to assist with health literacy for consumers and dissemination via the Waterloo Wellington Regional Nutrition Network We will also post the study on the web-based Ontario Nutrition Resource Centre an initiative of the Ontario Public Health Association
The DAWL study will be posted on the Canadian Inventory of Nutrition and Dietetic Associated Research CINDAR and Canadian Obesity Network CON websites and in the Members in Action section of the Dietitians of Canada newsletter The PI co-investigators and graduate students will collaborate on scientific publications and presentations at nutrition meetings eg Canadian Nutrition Society The research team will work with media specialists to reach and educate the public and with the agri-food chain industry not-for-profit trade association marketing group including Dairy Farmers of Canada Agropur Coopérative and Ultima Foods Dairy Farmers of Ontario Ontario Dairy Council
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None