Comparing Usual Care and Metabolic-Based Diet Plans in Obese Adults
Comparing Usual Care and Metabolic-Based Diet Plans in Obese Adults
Background: Usual care (UC) practice for weight management often includes providing standardised, ad libitum, low-calorie nutrition plans. However, weight loss using such plans appears comparable with metabolic-based diet (MD) plans that are closer to resting energy expenditure (REE) level. In addition, MD plans are approximately 250–750 kcal/day higher in caloric values compared with UC plans. Therefore, the purpose of this study was to compare weight loss and eating behaviour differences between UC and MD plans.
Methods: Seventy-four obese (30.0–51.7 kg/m) adults (21–67 years) voluntarily participated in a 24-week randomised study. UC men and women received a fixed, ad libitum, 1600 and 1200 kcal/day nutrient plan, respectively. MD participants received an individualised treatment plan based from measured REE. Bodyweight and eating behaviours (i.e. intake, restraint and uncontrolled eating) were assessed over time.
Results: Intent-to-treat analysis indicated no significant difference in weight loss (UC: −5.7 ± 6.3% vs. MD: −5.3 ± 7.1% p = 0.67) between groups over time. There was no difference in daily energy intake (UC: 2490 ± 576 kcal/day vs. MD: 2525 ± 475 kcal/day) at 24 weeks between groups. Both groups experienced a significant improvement (p < 0.05) in eating dietary restraint and uncontrolled eating yet there was no difference between groups.
Conclusion: From this study, UC calorie plans do not generate more weight loss or improve eating behaviours in comparison with MD calorie plans. As treatment effects are comparable, clinicians can select UC or MD plan options based on clinician and patient preference.
The three pillars to successful weight reduction programmes include reduced dietary intake, increased physical activity, and behaviour/lifestyle modification. Independently, reduced dietary intake appears to be most effective in weight reduction. Usual care (UC) practice within weight reduction clinical trials often use standardised, low-energy nutrition plans. Typically, women and men are provided or recommended a fixed low-energy diet plan (i.e. 1200–1600 kcal/day). These low-energy diet plans are designed to promote 0.5–1.0 kg/week weight reduction. Average weight reduction over 12–24 weeks on a standardised, ad libitum, low-energy diet appears to be −4 to −7 kg. However, adherence to these plans appears problematic as weight loss is less than what is normally predicted, energy absorption remains unaltered, and resting energy expenditure (REE) is relatively stable following modest weight reduction.
Early research indicated that severe dieting increases the prospective risk for future eating disorders. However, the National Task Force on the Prevention and Treatment of Obesity conducted a thorough analysis of published literature and concluded Concerns that dieting induces eating disorders or other psychological dysfunction in overweight and obese adults are generally not supported by empirical studies. In addition, a recent study offers further evidence that calorie restriction in the form of liquid meal replacements (i.e. 1000 kcal/day) or ad libitum (1200–1500 kcal/day) does not perpetuate eating disorders. Participant weight loss following the 1200–1500 kcal/day ad libitum diet was 7.8 ± 6.0% compared with 12.1 ± 6.7% with the 1000 kcal/day liquid meal replacement diet. Given such a large difference in percent weight change from a marginal difference in calorie plans, it is reasonable to assume that weight loss in the 1200–1500 kcal/day ad libitum diet group was less than expected. Based on these data, it may be deduced that the 1200–1500 kcal/day ad libitum diet group experienced similar difficulty adhering long-term as previously noted.
Researchers have demonstrated that consuming too few calories (i.e. 1000–1200 kcal/day) over time causes an increase in subjective hunger ratings from alterations in hunger related hormones (i.e. leptin and ghrelin) and this may affect adherence to standardised low-energy plans. By contrast, eating a level of calories closer to basal metabolic needs appears to minimise subjective levels of hunger. Researchers demonstrated that altered macronutrient energy plans of approximately 1950 kcal/day, over 12-week period, minimised the hunger effect even when serum ghrelin and leptin levels decreased over time.
A recent study that evaluated macronutrient-altered diets of 2100 kcal/day in predominately obese adults confirms these findings. Results from that study indicate a modest reduction (10%) in appetite following the 6-week diet period. Moreover, it appears a modest calorie level consisting of 25% protein results in a small, yet significant, reduction (i.e. 8%) in leptin values. Therefore, the combination of a higher calorie diet plan with varying macronutrient levels (i.e. higher protein content) may negate increased subjective ratings of hunger from slight alterations in eating behaviour hormones.
McDoniel et al. demonstrated overweight individuals may reduce bodyweight (−4.3 ± 3.3 kg) over a 12-week period with a balanced macronutrient, nutrition plan (est. 1700–1900 kcal/day) close to basal metabolic needs. In addition, Wiegle et al. demonstrated a decrease in bodyweight (est. −4 kg) over 120 days from the estimated 1950 kcal/day diet plan. However, Beasley et al. did not indicate if the obese participants experienced weight reduction following 2100 kcal/day, 6-week evaluation period. Based on these data, a macronutrient balanced calorie level that is close to basal metabolic needs appears to generate comparable weight loss to fixed 1200–1500 kcal/diet without a possible increase in subjective ratings of hunger.
Negative energy balance is the cornerstone to successful weight reduction. However, varying levels of negative energy balance should generate different amounts of weight loss. For example, a −250 kcal/day reduction from daily energy requirements for weight maintenance should promote ½ lb perweek weight loss. A continued reduction of 1000 kcal/day should result in a weight loss of 2 lbs per week. From the literature, it appears that weight loss using standardised, low-energy plans or low-energy nutrients plans close to basal metabolism are comparable over 12 weeks. However, severly restrictive diets well below basal metabolic needs may increase subjective ratings of hunger caused by alterations in eating behaviour hormones. By contrast, a balanced macronutrient diet plan close to basal metabolic needs, appears to reduce subjective ratings of hunger even when eating behaviour hormones significantly change Therefore, the purpose of this study was to evaluate the weight loss and eating behaviour effects using a fixed, low-energy diet compared with a metabolic-based diet in obese adults over time.
Abstract and Introduction
Abstract
Background: Usual care (UC) practice for weight management often includes providing standardised, ad libitum, low-calorie nutrition plans. However, weight loss using such plans appears comparable with metabolic-based diet (MD) plans that are closer to resting energy expenditure (REE) level. In addition, MD plans are approximately 250–750 kcal/day higher in caloric values compared with UC plans. Therefore, the purpose of this study was to compare weight loss and eating behaviour differences between UC and MD plans.
Methods: Seventy-four obese (30.0–51.7 kg/m) adults (21–67 years) voluntarily participated in a 24-week randomised study. UC men and women received a fixed, ad libitum, 1600 and 1200 kcal/day nutrient plan, respectively. MD participants received an individualised treatment plan based from measured REE. Bodyweight and eating behaviours (i.e. intake, restraint and uncontrolled eating) were assessed over time.
Results: Intent-to-treat analysis indicated no significant difference in weight loss (UC: −5.7 ± 6.3% vs. MD: −5.3 ± 7.1% p = 0.67) between groups over time. There was no difference in daily energy intake (UC: 2490 ± 576 kcal/day vs. MD: 2525 ± 475 kcal/day) at 24 weeks between groups. Both groups experienced a significant improvement (p < 0.05) in eating dietary restraint and uncontrolled eating yet there was no difference between groups.
Conclusion: From this study, UC calorie plans do not generate more weight loss or improve eating behaviours in comparison with MD calorie plans. As treatment effects are comparable, clinicians can select UC or MD plan options based on clinician and patient preference.
Introduction
The three pillars to successful weight reduction programmes include reduced dietary intake, increased physical activity, and behaviour/lifestyle modification. Independently, reduced dietary intake appears to be most effective in weight reduction. Usual care (UC) practice within weight reduction clinical trials often use standardised, low-energy nutrition plans. Typically, women and men are provided or recommended a fixed low-energy diet plan (i.e. 1200–1600 kcal/day). These low-energy diet plans are designed to promote 0.5–1.0 kg/week weight reduction. Average weight reduction over 12–24 weeks on a standardised, ad libitum, low-energy diet appears to be −4 to −7 kg. However, adherence to these plans appears problematic as weight loss is less than what is normally predicted, energy absorption remains unaltered, and resting energy expenditure (REE) is relatively stable following modest weight reduction.
Early research indicated that severe dieting increases the prospective risk for future eating disorders. However, the National Task Force on the Prevention and Treatment of Obesity conducted a thorough analysis of published literature and concluded Concerns that dieting induces eating disorders or other psychological dysfunction in overweight and obese adults are generally not supported by empirical studies. In addition, a recent study offers further evidence that calorie restriction in the form of liquid meal replacements (i.e. 1000 kcal/day) or ad libitum (1200–1500 kcal/day) does not perpetuate eating disorders. Participant weight loss following the 1200–1500 kcal/day ad libitum diet was 7.8 ± 6.0% compared with 12.1 ± 6.7% with the 1000 kcal/day liquid meal replacement diet. Given such a large difference in percent weight change from a marginal difference in calorie plans, it is reasonable to assume that weight loss in the 1200–1500 kcal/day ad libitum diet group was less than expected. Based on these data, it may be deduced that the 1200–1500 kcal/day ad libitum diet group experienced similar difficulty adhering long-term as previously noted.
Researchers have demonstrated that consuming too few calories (i.e. 1000–1200 kcal/day) over time causes an increase in subjective hunger ratings from alterations in hunger related hormones (i.e. leptin and ghrelin) and this may affect adherence to standardised low-energy plans. By contrast, eating a level of calories closer to basal metabolic needs appears to minimise subjective levels of hunger. Researchers demonstrated that altered macronutrient energy plans of approximately 1950 kcal/day, over 12-week period, minimised the hunger effect even when serum ghrelin and leptin levels decreased over time.
A recent study that evaluated macronutrient-altered diets of 2100 kcal/day in predominately obese adults confirms these findings. Results from that study indicate a modest reduction (10%) in appetite following the 6-week diet period. Moreover, it appears a modest calorie level consisting of 25% protein results in a small, yet significant, reduction (i.e. 8%) in leptin values. Therefore, the combination of a higher calorie diet plan with varying macronutrient levels (i.e. higher protein content) may negate increased subjective ratings of hunger from slight alterations in eating behaviour hormones.
McDoniel et al. demonstrated overweight individuals may reduce bodyweight (−4.3 ± 3.3 kg) over a 12-week period with a balanced macronutrient, nutrition plan (est. 1700–1900 kcal/day) close to basal metabolic needs. In addition, Wiegle et al. demonstrated a decrease in bodyweight (est. −4 kg) over 120 days from the estimated 1950 kcal/day diet plan. However, Beasley et al. did not indicate if the obese participants experienced weight reduction following 2100 kcal/day, 6-week evaluation period. Based on these data, a macronutrient balanced calorie level that is close to basal metabolic needs appears to generate comparable weight loss to fixed 1200–1500 kcal/diet without a possible increase in subjective ratings of hunger.
Negative energy balance is the cornerstone to successful weight reduction. However, varying levels of negative energy balance should generate different amounts of weight loss. For example, a −250 kcal/day reduction from daily energy requirements for weight maintenance should promote ½ lb perweek weight loss. A continued reduction of 1000 kcal/day should result in a weight loss of 2 lbs per week. From the literature, it appears that weight loss using standardised, low-energy plans or low-energy nutrients plans close to basal metabolism are comparable over 12 weeks. However, severly restrictive diets well below basal metabolic needs may increase subjective ratings of hunger caused by alterations in eating behaviour hormones. By contrast, a balanced macronutrient diet plan close to basal metabolic needs, appears to reduce subjective ratings of hunger even when eating behaviour hormones significantly change Therefore, the purpose of this study was to evaluate the weight loss and eating behaviour effects using a fixed, low-energy diet compared with a metabolic-based diet in obese adults over time.
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