The $12M NuSI/Ludwig Study ~ Part III: Some "Early" Lessons

In Part I, I discussed some problems with methodology, largely focusing on the reduced Run-In Phase that probably compromised the outcomes irreparably.

In Part II, I highlighted a critical issue with the Run-In Phase, the purpose of which was to produce a somewhat homogeneous”reduced weight state” to test various diets in maintenance of that state.

Finally, since randomization to the various test diets occurred after weight loss (PWL) randomization to maintenance evaluation diet wouldn’t influence the impact of various BSL (pre-weight reduction baseline) steps on the Run-In outcome — target = 12% ± 2 percent weight loss — on a standard composition diet for all:  45% Carb / 30% Fat / 25% Protein.

The researchers seem to have made minimal adjustments, if any, during the Run-In Weight Loss so as to produce a more uniform outcome.  Rather, the result was a wide range of weight loss (5.6 to 16.0%, approximately 10.5percent ± 5%). 

Thus we’ve got an”accidental” test-within-a-test of this CIH/TWICHOO from these”early” results.

In the end, I provide these scatter plots for all 105 subjects who successfully completed the study, for whom complete data for insulin steps and energy expenditure were available at all time points.

The Carb-Insulin Hypothesis (aka TWICHOO) forecasts that weight loss will vary inversely with insulin levels:  The greater the insulin levels, the lesser the weight loss.  The Run-In Stage data supports no such connection (indeed, if anything, absolute weight loss was greater for those with higher baseline insulin measures.

Meanwhile, differences in weight loss can easily be explained by variation in caloric deficit throughout the calorie restricted Run-In due to rough estimation of baseline energy expenditure (vs. rigorous measure).

This post expands on some relationships of baseline (BSL) and post-weight reduction (PWL) measures as observed during the weight loss portion of the Run-In Phase.