TABLE 3.
Sensitivity analyses for effects of Test diets varying in carbohydrate content on estimated energy requirement during weight-loss maintenance in the Framingham State Food Study1
| EER by diet group, kcal/d | Linear trend, kcal/d | |||||
|---|---|---|---|---|---|---|
| Analysis | Low-Carb | Moderate-Carb | High-Carb | P 2 | (Low-Carb) – (High-Carb) | P 3 |
| Adjusted for change in body composition by DXA 4 | ||||||
| 2572 (2442, 2702) | 2452 (2313, 2592) | 2304 (2145, 2462) | 0.04 | 268 (58, 478) | 0.01 | |
| Adjusted for change in body composition by isotope dilution 4 | ||||||
| 2481 (2330, 2631) | 2394 (2234, 2553) | 2208 (2027, 2388) | 0.08 | 273 (32, 513) | 0.03 | |
| Accounting for possible dietary nonadherence 5 | ||||||
| 2631 (2488, 2775) | 2369 (2208, 2531) | 2347 (2198, 2495) | 0.02 | 285 (76, 493) | 0.008 | |
| As above, with additional elimination of participants lacking nonadherence data 6 | ||||||
| 2637 (2501, 2773) | 2456 (2278, 2634) | 2345 (2190, 2499) | 0.02 | 292 (84, 501) | 0.007 | |
Values are means (95% CI). Data were calculated per kg and normalized to average weight of 82 kg at START, using model 2 (Table 2, PP) to examine how changes in body composition and potential nonadherence could influence the diet effect on EER. EER, estimated energy requirement; PP, per protocol analysis; START, start of randomized trial (postweight loss, prerandomization); TEE, total energy expenditure measured using DLW methodology.
P value is for the overall diet group effect.
P value for (Low-Carb) – (High-Carb) contrast is equivalent to a test for linear trend across diet groups (with equal, 20% increments in the contribution of carbohydrate to total energy intake from Low-Carb to Moderate-Carb and from Moderate-Carb to High-Carb).
N = 110 (DXA), N = 109 (isotope dilution). Analyses were adjusted for change in body composition between weeks 10 and 20 of the Test phase. One participant had unusable isotope dilution data at MID and END.
N = 65. Participants (N = 45) were excluded if the EER-to-TEE ratio was in the top quintile (i.e., individuals most likely to have underconsumed provided foods) or bottom quintile (i.e., individuals most likely to have consumed foods off protocol).
N = 56. Additional participants (N = 9) from cohort 1 were excluded because data were missing for unconsumed energy.
DLW, doubly labeled water.