Limits...
Tailoring dietary approaches for weight loss.

Gardner CD - Int J Obes Suppl (2012)

Bottom Line: From a glass half full perspective, this suggests that there is more than one choice for a dietary approach to lose weight, and that Low-Fat and Low-Carb diets may be equally effective.However, before throwing out the half-glass of water, it is worthwhile to consider that focusing on average results may mask important subgroup successes and failures.Several studies have now reported that adults with greater insulin resistance are more successful with weight loss on a lower-carbohydrate diet compared with a lower-fat diet, whereas adults with greater insulin sensitivity are equally or more successful with weight loss on a lower-fat diet compared with a lower-carbohydrate diet.

View Article: PubMed Central - PubMed

Affiliation: Division of Stanford Prevention Research Center, Department of Medicine, Stanford University , Stanford, CA, USA.

ABSTRACT
Although the 'Low-Fat' diet was the predominant public health recommendation for weight loss and weight control for the past several decades, the obesity epidemic continued to grow during this time period. An alternative 'low-carbohydrate' (Low-Carb) approach, although originally dismissed and even vilified, was comparatively tested in a series of studies over the past decade, and has been found in general to be as effective, if not more, as the Low-Fat approach for weight loss and for several related metabolic health measures. From a glass half full perspective, this suggests that there is more than one choice for a dietary approach to lose weight, and that Low-Fat and Low-Carb diets may be equally effective. From a glass half empty perspective, the average amount of weight lost on either of these two dietary approaches under the conditions studied, particularly when followed beyond 1 year, has been modest at best and negligible at worst, suggesting that the two approaches may be equally ineffective. One could resign themselves at this point to focusing on calories and energy intake restriction, regardless of macronutrient distributions. However, before throwing out the half-glass of water, it is worthwhile to consider that focusing on average results may mask important subgroup successes and failures. In all weight-loss studies, without exception, the range of individual differences in weight change within any particular diet groups is orders of magnitude greater than the average group differences between diet groups. Several studies have now reported that adults with greater insulin resistance are more successful with weight loss on a lower-carbohydrate diet compared with a lower-fat diet, whereas adults with greater insulin sensitivity are equally or more successful with weight loss on a lower-fat diet compared with a lower-carbohydrate diet. Other preliminary findings suggest that there may be some promise with matching individuals with certain genotypes to one type of diet over another for increasing weight-loss success. Future research to address the macronutrient intake component of the obesity epidemic should build on these recent insights and be directed toward effectively classifying individuals who can be differentially matched to alternate types of weight-loss diets that maximize weight-loss and weight-control success.

No MeSH data available.


Related in: MedlinePlus

The 12-month weight change of individual study participants who completed the full study protocol of the A TO Z Study, by diet group, ordered from greatest loss to greatest gain. Each bar represents an individual study participant. Missing data for 12, 23, 24 and 22% for the Atkins, Zone, LEARN and Ornish groups, respectively.
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fig1: The 12-month weight change of individual study participants who completed the full study protocol of the A TO Z Study, by diet group, ordered from greatest loss to greatest gain. Each bar represents an individual study participant. Missing data for 12, 23, 24 and 22% for the Atkins, Zone, LEARN and Ornish groups, respectively.

Mentions: The heterogeneity of individual responsiveness to weight-loss diets is substantial. As is standard in scientific publications, most weight-loss studies present average group responses with some measure of variance (for example, s.d., s.e.m., 95% CI), rather than presenting individual raw data. When presenting data this way, it is easy to fail to appreciate the magnitude of the typical range of individual variability in these weight-loss studies. In a two-arm weight-loss trial among 146 overweight or obese adults comparing a Low-Carb ketogenic diet to a Low-Fat diet plus orlistat, after 48 weeks the average weight loss in both groups was approximately 10% of baseline weight and not different between groups, but within both groups the individual weight loss ranged from small amounts of weight gain to approximately 30% weight loss (a range of >40 kg (>90 lbs) of weight change within each group).19 In a four-arm weight-loss trial among 160 overweight and obese adults comparing Atkins, Zone, Weight Watchers and Ornish, after 12 months the average weight loss across all four groups was 4–7 kg (excluding drop-outs), but within all four groups the range included some individuals who gained ⩾5 kg and some who lost ⩾15 kg (a range of ∼23 to ∼40 kg (∼50 to ∼90 lbs) of weight change within each diet group).8 The individual results for 12-month completers in our own A TO Z Study (80% retention at 12 months) are presented in Figure 1. In the A TO Z Study, the average weight loss at 12 months among the 311 overweight or obese women assigned to Atkins, Zone, LEARN or Ornish was 2–5 kg (∼4–11 lbs; carrying baseline forward for drop-outs and missing data), but within all four groups the range of weight change was from gaining ⩾5 kg to losing ⩾15 kg (a range of ∼30 to ∼35 kg (∼65 to ∼75 lbs) of weight change within each diet group). Therefore, although the magnitude of the average weight loss in the Low-Fat vs Low-Carb diet studies and the differences between assigned groups have been modest, the tremendous variability of results within each assigned diet group suggests that these substantially different individual responses to the same diets merit further investigation.


Tailoring dietary approaches for weight loss.

Gardner CD - Int J Obes Suppl (2012)

The 12-month weight change of individual study participants who completed the full study protocol of the A TO Z Study, by diet group, ordered from greatest loss to greatest gain. Each bar represents an individual study participant. Missing data for 12, 23, 24 and 22% for the Atkins, Zone, LEARN and Ornish groups, respectively.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4109087&req=5

fig1: The 12-month weight change of individual study participants who completed the full study protocol of the A TO Z Study, by diet group, ordered from greatest loss to greatest gain. Each bar represents an individual study participant. Missing data for 12, 23, 24 and 22% for the Atkins, Zone, LEARN and Ornish groups, respectively.
Mentions: The heterogeneity of individual responsiveness to weight-loss diets is substantial. As is standard in scientific publications, most weight-loss studies present average group responses with some measure of variance (for example, s.d., s.e.m., 95% CI), rather than presenting individual raw data. When presenting data this way, it is easy to fail to appreciate the magnitude of the typical range of individual variability in these weight-loss studies. In a two-arm weight-loss trial among 146 overweight or obese adults comparing a Low-Carb ketogenic diet to a Low-Fat diet plus orlistat, after 48 weeks the average weight loss in both groups was approximately 10% of baseline weight and not different between groups, but within both groups the individual weight loss ranged from small amounts of weight gain to approximately 30% weight loss (a range of >40 kg (>90 lbs) of weight change within each group).19 In a four-arm weight-loss trial among 160 overweight and obese adults comparing Atkins, Zone, Weight Watchers and Ornish, after 12 months the average weight loss across all four groups was 4–7 kg (excluding drop-outs), but within all four groups the range included some individuals who gained ⩾5 kg and some who lost ⩾15 kg (a range of ∼23 to ∼40 kg (∼50 to ∼90 lbs) of weight change within each diet group).8 The individual results for 12-month completers in our own A TO Z Study (80% retention at 12 months) are presented in Figure 1. In the A TO Z Study, the average weight loss at 12 months among the 311 overweight or obese women assigned to Atkins, Zone, LEARN or Ornish was 2–5 kg (∼4–11 lbs; carrying baseline forward for drop-outs and missing data), but within all four groups the range of weight change was from gaining ⩾5 kg to losing ⩾15 kg (a range of ∼30 to ∼35 kg (∼65 to ∼75 lbs) of weight change within each diet group). Therefore, although the magnitude of the average weight loss in the Low-Fat vs Low-Carb diet studies and the differences between assigned groups have been modest, the tremendous variability of results within each assigned diet group suggests that these substantially different individual responses to the same diets merit further investigation.

Bottom Line: From a glass half full perspective, this suggests that there is more than one choice for a dietary approach to lose weight, and that Low-Fat and Low-Carb diets may be equally effective.However, before throwing out the half-glass of water, it is worthwhile to consider that focusing on average results may mask important subgroup successes and failures.Several studies have now reported that adults with greater insulin resistance are more successful with weight loss on a lower-carbohydrate diet compared with a lower-fat diet, whereas adults with greater insulin sensitivity are equally or more successful with weight loss on a lower-fat diet compared with a lower-carbohydrate diet.

View Article: PubMed Central - PubMed

Affiliation: Division of Stanford Prevention Research Center, Department of Medicine, Stanford University , Stanford, CA, USA.

ABSTRACT
Although the 'Low-Fat' diet was the predominant public health recommendation for weight loss and weight control for the past several decades, the obesity epidemic continued to grow during this time period. An alternative 'low-carbohydrate' (Low-Carb) approach, although originally dismissed and even vilified, was comparatively tested in a series of studies over the past decade, and has been found in general to be as effective, if not more, as the Low-Fat approach for weight loss and for several related metabolic health measures. From a glass half full perspective, this suggests that there is more than one choice for a dietary approach to lose weight, and that Low-Fat and Low-Carb diets may be equally effective. From a glass half empty perspective, the average amount of weight lost on either of these two dietary approaches under the conditions studied, particularly when followed beyond 1 year, has been modest at best and negligible at worst, suggesting that the two approaches may be equally ineffective. One could resign themselves at this point to focusing on calories and energy intake restriction, regardless of macronutrient distributions. However, before throwing out the half-glass of water, it is worthwhile to consider that focusing on average results may mask important subgroup successes and failures. In all weight-loss studies, without exception, the range of individual differences in weight change within any particular diet groups is orders of magnitude greater than the average group differences between diet groups. Several studies have now reported that adults with greater insulin resistance are more successful with weight loss on a lower-carbohydrate diet compared with a lower-fat diet, whereas adults with greater insulin sensitivity are equally or more successful with weight loss on a lower-fat diet compared with a lower-carbohydrate diet. Other preliminary findings suggest that there may be some promise with matching individuals with certain genotypes to one type of diet over another for increasing weight-loss success. Future research to address the macronutrient intake component of the obesity epidemic should build on these recent insights and be directed toward effectively classifying individuals who can be differentially matched to alternate types of weight-loss diets that maximize weight-loss and weight-control success.

No MeSH data available.


Related in: MedlinePlus