THE EFFECTS OF MODERATE CALORIC RESTRICTION AND EXERCISE ON BODY MASS, WAIST TO HIP RATIO, AND VISCERAL FAT DISTRIBUTION.

Transcription

1 THE EFFECTS OF MODERATE CALORIC RESTRICTION AND EXERCISE ON BODY MASS, WAIST TO HIP RATIO, AND VISCERAL FAT DISTRIBUTION Chung-Bang Weng A plan B paper submitted in partial fulfillment of the requirements for the degree of Master of Arts Department of Physical Education and Sports Central Michigan University Mount Pleasant, Michigan May, 2000

2 TABLE OF CONTENTS INTRODUCTION... 2 REVIEW OF RELATED LITERATURE... 3 METHODS...5 RESULTS... 8 DISCUSSION Appendix A Appendix B Appendix C Appendix D Appendix E BIBLIOGRAPHY

3 INTRODUCTION Obesity has become a prevalent health problem in the United States of America and has expanded to the whole world in recent years. Although obesity is not an acute disease, it is identified as a risk factor for some diseases, such as hypertension, cardiovascular disease, cancers, and diabetes (ACSM-CDC, 1995). Clearly, a reduction in body weight would be beneficial for the regression of these diseases, especially a reduction in the visceral adipose tissue. Egger (1992) reviewed studies which showed a clear association between abdominal obesity and a range of ailments including coronary events, hypertension, blood lipid level, cholecystectomy, diabetes, and gallbladder disease. He concluded that the association between waist to hip ratio and risk indicators appears to be dose related. Therefore, weight management should be a major focus in the public health arena. The main factors of this health problem are eating disorders and sedentary lifestyles. According to the National Cholesterol Educational Program (NCEP), caloric restriction, physical activity and behavior modification are the best ways to fight against obesity. A comprehensive weight loss program should include each of these aspects. Several aspects of the comorbidities of overweight and obesity are being explored to indicate that the visceral fat distribution is related to several chronic diseases, such as hypertension, coronary heart disease, and diabetes. Recent study indicated several methods to predict the visceral fat distribution, such as computer tomography, waist circumference, waist to hip ratio, and sagittal diameter. The result of this study will hopefully lead to a better understanding of the weight loss effect on visceral fat distribution, which will be examined by waist circumference, waist to hip ratio, and sagittal diameter. 02

4 Energy Restriction and Weight Loss REVIEW OF RELATED LITERATURE The restriction of energy intake has long been utilized as effective means of weight loss. Furthermore, the degree of caloric restriction is related to the magnitude of weight reduction. Smith and Zachwieja (1999) reviewed the obesity intervention strategies regarding the effect of caloric restriction, pharmacological intervention, and exercise to promote the loss of visceral adipose tissue (VAT). They found that VLCDs and LCDs usually parallels the rate of weight loss, and does not appear to influence the VAT and fat mass rate. However, there are strong data to support that VAT decrease significantly. Exercise and Weight Loss In order for weight loss to be successful, a negative energy balance must be achieved. That is, caloric expenditure must be greater than caloric intake. Houmard et al. (1993) investigated the effects of exercise training on absolute and relative measurements of regional adiposity. The exercise training program consisted of ground and/or treadmill walking and /or running 70-80% of maximal heart rate three days a week. There were significant reductions in sagittal diameter, waist circumference, and WHR. In addition, the exercise program resulted in a reduction of these girths in virtually all of the subjects. Weight Loss and Changes in Waist, Hip and WHR The body composition should change since energy restriction and exercise improved the weight loss. As long as body weight changed, fat distribution would change as well. Waist circumference and WHR are the easy methods to determine this change. A study by Kahn, Young, and Gelskey (1996) showed WHR is an index of central obesity. There is also evidence that people with large waists may be at high risk of disease and have greater difficulty performing routine daily tasks. 03

5 A study by Caan, et al. (1994) investigated the changes in measurements of body fat distribution accompanying weight change. The results did not show a significant decrease in waist circumference and WHR with body weight loss; however, the results suggested that weight gain is almost always accompanied by a significant increase in WHR. Weight Loss and Visceral Fat Distribution Computerized Tomography (CT), is a precise tool to assess the visceral fat distribution. Because of the high price of CT, sagittal diameter measurement is an alternative method to assess the visceral fat distribution when the research budget is limited. Tornaghi et al. (1994) compared CT (L4-L5) adipose tissue area accuracy to WHR, sagittal diameter, and ultrasonic measurements of intra-abdominal depth. Correlation coefficient between visceral adipose tissue and sagittal diameter (r = 0.77) was higher than visceral adipose tissue and WHR (r = 0.73). A study by Kvist et al. (1988) showed that sagittal diameter of the trunk at the L3-L5 level can be a good predictor of visceral adipose tissue. Stallone et al. (1991) investigated weight loss and body fat distribution. Their program included a very low calorie diet and behavior therapy to promote weight loss. The results showed that the weight loss included a significant decrease of visceral adipose tissue. They also concluded that the relationship between waist circumference and visceral adipose tissue is highly related. Statement of the Problem The purpose of this study was to determine the effects of body weight changes on waist to hip ratio and the visceral fat distribution in a community weight loss program. 04

6 METHODS Subjects: Forty-five obese subjects, 13 males and 32 females, ages (mean = 47) years old, were recruited through advertisements. All subjects signed an informed consent prior to participation. Dietary Protocol: The Diet That Lets you Cheat is a commercially available low-calorie diet program, which emphasizes the importance of exercise and the role of behavior modification. This 1200 kcal/day diet consisted of three phases. Each phase allowed a weekly cheat of 300 calories. Phase I lasted two weeks during which the subjects followed a strict menu. Adherence to the prescribed food choices was emphasized, as the habits encouraged during this phase would impact the overall success of the program. In the diet, the subjects were instructed to eat breakfast every day, pay close attention to portion size, and follow a pre-planned menu. While this portion of the diet allowed for very little flexibility, it gave the subjects a chance to appreciate the quantity of food that constituted 1200 calories, learn more about healthy food choices, and plan the best mealtimes. Phase I of The Diet That Lets you Cheat lasted two weeks. In Phase II, the diet program become more flexible. In Phase I, a weekly menu was set and the intention was that it would be followed with very few changes by the subjects. Phase II allowed for limited exchanges within the recommended food choices, depending on personal preference. For example, four ounces of turkey could be exchanged for four ounce of chicken. Exchanges were allowed within food groups as indicated by the dietary exchange lists developed by the American Diabetes Association and the American Dietetic Association (Caso, 1950). The subjects were also allowed some flexibility in planning their meals and snacks were permitted, provided total daily caloric intake did 05

7 not exceed 1200 kcals. This phase emphasized responsible meal planning based on hunger and individual preferences while limiting total calories by encouraging healthy eating. To assist the subjects in planning their meals, charts were distributed that allowed them to keep track of the number of servings of each food exchange they had eaten, thereby giving them a visual representation of their adherence. Phase II also lasted two weeks. For the remainder of the weight loss program the subjects were in Phase III, which allowed for full exchanges within food exchanges. The subjects were also allowed to eat foods not presented in the diet program, like prepare meals and fast food. As in Phase II, making healthy choices was emphasized. The meal planning charts were an important tool in tracking daily calories and food selections. Phase III also allowed for a weekly cheat of 300 kcals or less. By incorporating this extra allowance, the subjects could eat something they enjoyed without feeling guilty. The emphasis of this phase was realizing a diet the subjects could live with through making healthy food choices and careful attention to what they were eating. Phase III lasted for the reminding 6 weeks of the study. The subjects were also encouraged to revert back to Phase I or II if they were having trouble adhering to the 1200 kcal limit. Weekly meeting were conducted by the research team and focused on techniques for successful food choice, exchanges, and adherence to the diet. The subjects were encouraged to share their own experience with the diet. These weekly meeting also served as a time for the weekly body mass measurement. Exercise Protocol: The Diet That Lets you Cheat emphasizes the importance of exercise in a weight loss program. Specifically, low-intensity, long duration bouts of physical activity are 06

8 emphasized in this program. The duration of exercise progressed along with the phases of the diet. During Phase I, 20 minutes of exercise was required daily, during Phase II, 40 minutes, and during Phase III the subjects progressed to 60 minutes of activity each day. The subjects were encouraged to walk as the primary mode of activity, but they could complement walking with other modes of exercise. The total daily exercise had to add up to a total of 20, 40, 60 minutes, seven days per week. It is important to note that if subjects in this program already took part in some planned leisure activities, such as racquetball or golf, this was considered exercise for the purpose of this study. If these planned activities did not meet the required time, the subjects were asked to supplement the activities with walking to accumulate the required time. Laboratory Testing: The body weight for each subject was measured on a calibrated laundry scale at Wellness Central and was reported to the nearest pound. Initial body weight, waist and hip circumference, and sagittal diameter were measured at an informational meeting one week prior to the start of the treatments. Throughout the study, body weight was measured at weekly Tuesday evening education meetings. Final body weight was determined the week following the end of treatments. This allowed body weight data to be collected at pretest, posttest, and weekly during the study. Body weight, waist and hip circumference, and sagittal diameter were also recorded at the end of phases I and II but not analyzed for this study (Appendix A-D). Total and visceral fat were estimated by Kvist s equation (1988) with weight-height ratio and sagittal diameter. In order to increase the reliability and estimate accurately, waist and hip girth and sagittal diameter had to measure in optimal sites. 07

9 Waist circumference was measured at the minimal abdominal girth to the nearest 0.5 cm. Hip circumference was measured at the maximal protrusion of the buttocks to the nearest 0.5 cm. WHR was calculated by dividing the waist girth by the hip girth. Sagittal diameter is obtained by measuring the distance from the examination table to a horizontal spirit level placed over the abdominal of a recumbent subject at the level of the iliac crest. The measurement is performed after a normal expiration. These data were only collected at pretest and posttest. Statistical Analysis: In the analysis of the data collected in this study, the following statistics were used: Related t-tests were used in the determination of significance of pretest and posttest. The.05 level of significance was used in evaluating t-test results. In order to determine the significant changes in weight loss, waist and hip circumference changes, and total and visceral adipose tissue changes between males and females, independent t- tests were used. The.05 level of significance was used in evaluating t-test results. Finally, correlation tests were used to determine the relationships between weight loss, waist and hip circumference changes, sagittal diameter changes, and total and visceral adipose tissue changes. RESULTS Descriptive data along with the results of the laboratory pretest and posttest are shown in Table 1. The posttest data are less than the pretest data in each single measurement. Every subject lost weight after this ten-week treatment and the average is 15.3 pounds (Range lbs). (Appendix E). 08

10 Table 1: Descriptive data of subjects Descriptive Pretest Posttest Descriptive Pretest Posttest Subjects 45 Waist (inches) 39.98± ±5.04 Number men 13 Hip (inches) 46.04± ±4.98 Number Women 32 Sagittal Diameter ± ±1.20 (inches) Age (years) 47.13±12.07 WHR ± ±0.008 Height (inches) 67.02±3.21 TAT 2 (kg) 47.16± ±15.41 Weight (lbs) ± ±36.17 VAT 3 (kg) 3.73± ±1.92 % Fat 41.1± ±9.2 LBM 4 (lbs) ± ±23.73 BMI 32.93± ±5.25 Weight Loss 15.31± Waist to Hip Ratio. 3. Visceral Adipose Tissue. 2. Total Adipose Tissue. 4. Lean Body Mass. Related (paired) t-tests were determined to test the significance between the pretest and posttest. Table 2 shows weight, waist and hip girth, sagittal diameter, and total adipose tissue are significant different between pretest and posttest (p<001). In addition, WHR, visceral adipose tissue, and lean body mass are significant different between pretest and posttest (p<.05). Table 2: Paired Samples Test Source of Variation Paired Differences t Sig. (2-tailed) Mean Std. Deviation Std. Error Mean Weight 1 VS Weight ** Waist 1 VS Waist ** Hip 1 VS Hip ** Ratio 1 VS Ratio * SD 1 VS SD ** Total AT 1 VS Total AT ** Visceral AT1 VS Visceral AT * LBM1 VS LBM * * significant difference p <.05 ** significant different p<.001 Tables 3 and 4 show the data for men and women. Men had higher test results in pretest and lost more than women in most of the measurements, such as waist, hip, 09

11 sagittal diameter, and total adipose tissue. However, men increased the visceral adipose tissue by.3837 liters. Table 3: Pre-Post Test data for men and women Gender N Mean Std. Deviation Waist 1 male female Waist 4 male female Hip 1 male female Hip 4 male female WHR 1 male female WHR 4 male female SD 1 male female SD 4 male female Total AD 1 male female Total 4 male female Visceral 1 male female Visceral 4 male female Table 4: Pre-Post Test changes in men and women Gender N Mean Std. Deviation Waist Loss male female Hip Loss male female SD Loss male female TAT Loss male female VAT Loss male female Weight Loss male female

12 Table 5shows significant difference between men s and women s total adipose tissue (p<.001) and weight loss (p =.002). Comparing these data to Table 4, it is shown that men s weight loss and total adipose tissue loss were significantly better than women s. Table 5: Independent sample t-test: Men compared to women t df Sig. (2-tailed) Waist Loss Hip Loss SD Loss TAT Loss ** VAT Loss Weight loss * * significant difference p <.05; ** significant different p<.001 Table 6 shows the correlation between weight loss, waist and hip circumference changes, sagittal diameter changes, and total and visceral adipose tissue changes. We can find that weight loss is highly correlated to total adipose tissue, sagittal diameter loss, and waist loss. There is also a high correlation between total adipose tissue and sagittal diameter. Additionally, there is a very high correlation between sagittal diameter and visceral adipose tissue because sagittal diameter was used to estimate the visceral adipose tissue. Table 6: Correlations weight loss VAT Loss TAT Loss SD Loss Hip Loss Waist Loss Weight loss Pearson Correlation **.555** ** Sig. (2-tailed) VAT Loss Pearson Correlation *.638** Sig. (2-tailed) TAT Loss Pearson Correlation.696** -.340* ** * Sig. (2-tailed) SD Loss Pearson Correlation.555**.638**.384** Sig. (2-tailed) Hip Loss Pearson Correlation Sig. (2-tailed) Waist Loss Pearson Correlation.486** * Sig. (2-tailed) ** Correlation is significant at the 0.01 level (2-tailed). * Correlation is significant at the 0.05 level (2-tailed). 11 0

13 DISCUSSION This program focuses on the weight loss by moderate caloric restriction and exercise. These results suggest subjects lost significant body mass during this ten-week program. That means The Diet That Lets you Cheat is effective for weight loss. This study also examined the effect of weight loss on WHR and visceral adipose tissue. Data shows there are significant difference in waist and hip circumference changes, sagittal diameter, and total adipose tissues. These findings are consistent with Houmard, et al., (1993), who, showed an exercise program did induce significant reductions in sagittal diameter, waist circumference, and WHR. In addition, Smith et al. (1999) found that a significant difference from a very low caloric diet and visceral adipose tissue changes. The decrease of total adipose tissue, sagittal diameter, and waist circumference are highly correlated to the weight loss. Stallone et al. (1991) investigated weight loss and body fat distribution. He found the relationship between waist circumference and visceral adipose tissue is highly related. This study also investigated the difference between males and females. Overall, men seem had better improvement than women. These results may be explained by the best that men had larger measurements than women in the pretest. In conclusion, this study investigated the effects of moderate caloric restriction and exercise on body mass, WHR, and visceral far distribution. The results should significantly changed in weight, WHR, and visceral adipose tissue in both males and females. We also found that the decrease of total adipose tissue, sagittal diameter, and waist circumference were highly correlated to the weight loss. 12 0

14 Appendix A Test 1, January 4, 2000 Subjects Weekly Age Height Weight BMI % Fat LBM attendance (inch) (Lbs) Fat Weight (Lbs) 1 MB JB AB RB CB RB JB GC GC EC JC BC TD DD MD KE JF MF MF LG JH BK DK TL EL CL BL CL LM CM

15 Appendix A Continued Test 1, January 4, 2000 Subjects Weekly Age Height Weight BMI % Fat LBM attendance (inch) (Lbs) Fat Weight (Lbs) 31 EM BM AO RP JP JP CR SR BR ER JS LS LS JS GW

16 Appendix A Continued Test 1, January 4, 2000 Subjects Waist Hip W/H Sagittal Total Visceral Subcut. Diameter AT AT AT 1 MB JB AB RB CB RB JB GC GC EC JC BC TD DD MD KE JF MF MF LG JH BK DK TL EL CL BL CL LM CM

17 Appendix A Continued Test 1, January 4, 2000 Subjects Waist Hip W/H Sagittal Diameter Total AT Visceral AT Subcut. AT 31 EM BM AO RP JP JP CR SR BR ER JS LS LS JS GW Males Total Adipose Tissue = 1.36* weight/height 42.0 (liters) Visceral Adipose Tissue = 0.731* SD 11.5 (liters) Females Total Adipose Tissue = 1.61* weight/height 38.3 (liters) Visceral Adipose Tissue = 0.370* SD 4.85 (liters) Adipose Tissue (AT), Kg = AT, liter * Subcut. AT = Total AT Visceral AT Weight/Height in Kg/m. SD, Sagittal Diameter in cm. 16 0

18 Appendix B Test 2, January 18, 2000 Subjects Weekly Age Height Weight BMI % Fat LBM attendance (inch) (Lbs) Fat Weight (Lbs) 1 MB JB AB RB CB RB JB GC GC EC JC BC TD DD MD KE JF MF MF LG JH BK DK TL EL CL BL CL LM CM

19 Appendix B Continued Test 2, January 18, 2000 Subjects Weekly Age Height Weight BMI % Fat LBM attendance (inch) (Lbs) Fat Weight (Lbs) 31 EM BM AO RP JP JP CR SR BR ER JS LS LS JS GW

20 Appendix B Continued Test 2, January 18, 2000 Subjects Waist Hip W/H Sagittal Total Visceral Subcut. Diameter AT AT AT 1 MB JB AB RB CB RB JB GC GC EC JC BC TD DD MD KE JF MF MF LG JH BK DK TL EL CL BL CL LM CM

21 Appendix B Continued Test 2, January 18, 2000 Subjects Waist Hip W/H Sagittal Total Visceral Subcut. Diameter AT AT AT 31 EM BM AO RP JP JP CR SR BR ER JS LS LS JS GW

22 Appendix C Test 3, February 1, 2000 Subjects Weekly Age Height Weight BMI % Fat LBM attendance (inch) (Lbs) Fat Weight (Lbs) 1 MB JB AB RB CB RB JB GC GC EC JC BC TD DD MD KE JF MF MF LG JH BK DK TL EL CL BL N/A.. 28 CL LM CM

23 Appendix C Continued Test 3, February 1, 2000 Subjects Weekly Age Height Weight BMI % Fat LBM attendance (inch) (Lbs) Fat Weight (Lbs) 31 EM BM AO RP JP JP CR SR BR ER JS LS LS JS GW

24 Appendix C Continued Test 3, February 1, 2000 Subjects Waist Hip W/H Sagittal Total Visceral Subcut. Diameter AT AT AT 1 MB JB AB RB CB RB JB GC GC EC JC BC TD DD MD KE JF MF MF LG JH BK DK TL EL CL BL CL LM CM

25 Appendix C Continued Test 3, February 1, 2000 Subjects Waist Hip W/H Sagittal Total Visceral Subcut. Diameter AT AT AT 31 EM BM AO RP JP JP CR SR BR ER JS LS LS JS GW

26 Appendix D Test 4 March 7, 2000 Subjects Weekly Age Height Weight BMI % Fat LBM attendance (inch) (Lbs) Fat Weight (Lbs) 1 MB JB AB RB CB RB JB GC GC EC JC BC TD DD MD KE JF MF MF LG JH BK DK TL EL CL BL CL LM CM

27 Appendix D Continued Test 4 March 7, 2000 Subjects Weekly Age Height Weight BMI % Fat LBM attendance (inch) (Lbs) Fat Weight (Lbs) 31 EM BM AO RP JP JP CR SR BR ER JS LS LS JS GW

28 Appendix D Continued Test 4 March 7, 2000 Subjects Waist Hip W/H Sagittal Total Visceral Subcut. Diameter AT AT AT 1 MB JB AB RB CB RB JB GC GC EC JC BC TD DD MD KE JF MF MF LG JH BK DK TL EL CL BL CL LM CM

29 Appendix D Continued Test 4 March 7, 2000 Subjects Waist Hip W/H Sagittal Diameter Total AT Visceral AT Subcut. AT 31 EM BM AO RP JP JP CR SR BR ER JS LS LS JS GW

30 Appendix E Difference between T1 (1-4-00) --- T4 (3-7-00) Subjects Weight BMI % Fat LBM Waist Hip WHR Sagittal TAT VAT Subcut. Fat Weight Diameter AT 1 MB JB AB RB CB RB JB GC GC EC JC BC TD DD MD KE JF MF MF LG JH BK DK TL EL CL BL CL LM CM

31 Appendix E Continued Difference between T1 (1-4-00) --- T4 (3-7-00) Subjects Weight BMI % Fat LBM Waist Hip WHR Sagittal TAT VAT Subcut. Fat Weight Diameter AT 31 EM BM AO RP JP JP CR SR BR ER JS LS LS JS GW means increased. For example, subject 2 s VAT is It means he/she increased VAT by.66 kg. 30 0

32 BIBLIOGRAPHY Caan Bette, Mary Anne Armstrong, Joseph V. Selby, Marianne Sadler, Aaron R. Folsom, David Jacobs, Martha L. Slattery, Joan E Hilner and Jeffery Roseman. Changes in Measurements of body fat distribution accompanying weight change. International Journal of Obesity. 1994; 18: Caso, E.K. Calculation of diabetic diets. Journal of the American Dieteic Association, 1950; 26, Center for Disease and Prevention and the American College of Sports Medicine. Physical activity and public health. JAMA. 1995; 273: Egger Garry. The case for using waist to hip ratio measurements in routine medical checks. The Medical Journal of Australia. 1992; 156: Houmard Joseph A., Catherine McCullery, Linad K. Roy, Robert K. Bruner, Michael R. McCammon and Richard G. Israel. Effects of exercise training on absolute and relative measurements of regional adiposity. International Journal of Obesity. 1994; 18: Kahn Henry S., T. Kue Young and Dale Gelskey. The waist-to-hip ration as an index of central obesity. JAMA. 1996; 275: Kvist Henry, Badrul Chowdhury, Ulla Grangard, Ulf Tylen, and Lars Sjostrom. Total and visceral adipose-tissue volumes derived from measurements with computer tomography in adult men and women: predictive equations. American Journal of Clinical Nutrition 1998; 48: Parr, R.B, Bachman, D.C., and Noble, H.B. The Diet That Lets You Cheat. New York: Crown Publishers, Inc Smith SR, and JJ Zachwieja. Visceral adipose tissue: a critical review of intervention strategies. International Journal of Obesity. 1999; 23: Stallone Dayth D., Albert J. Stunkard, Thomas A. Wassen, Gary D. Foster, Jeffery Boorstein and Peter Arger. Weight loss and body fat distribution: a feasibility study using computer Tomography. International Journal of Obesity. 1991; 15: Tornaghi Giulio, Riccardo Raiteri, Carlo Pozzato, Anna Rispoli, Maurizio Bramani, Marco Cipolat and Angelo Craveri. Anthropometric or ultrasonic measurement in assessment of visceral fat? A comparative study. International Journal of Obesity. 1994; 18: