Figure 1.
Flow of Participants through the CALERIE trial at Pennington Biomedical Research Center.
Table 1.
Principal Components Analyses (PCA) for Fasting to Postprandial Changes in Metabolites.*
Table 2.
Median and interquartile range (IQR) of fasting and postprandial concentrations of metabolites at baseline (n = 46).*
Figure 2.
Trajectories of Fasting to Postprandial Metabolic Intermediate Concentration Changes over Time by Intervention Group.
Fasting to postprandial difference (FPPD) scores were computed as postprandial minus fasting concentration. Difference scores were used in principal component analyses and single component solutions were retained as described in Results. FPPD component scores in Figures A-C were calculated as: (1) FPPD = S1*(I1)+S2*(I2) +… Sk*(Ik); where: I1-ik are the k individual items used in the principal components analysis; S1–Sk are standardized scoring coefficients from the principal component analysis; and, I1-Ik are entered as (I/SdI) for each item. With equation 1, the FPPD component score is the average of the mean post-preprandial differences across items with each item weighted by its standardized scoring coefficient. Mean difference are expressed in standard deviation units. Significant trends (P<0.10) are identified with an asterisk (*) and significant group by time interactions are indicated with a (†). CR = Caloric restriction. CR+EX = Combined caloric restriction and exercise. LCD = Liquid calorie diet. A. Free Fatty Acids (FFA). (CR * 3 months P = 0.07) B. Acylcarnitines (AC). (CR * 3 months P = 0.02; CR * 6 month P = 0.002; CR+EX * 3 month P = 0.09; CR+EX * 6 month P = 0.08) C. Amino Acids (AA).
Figure 3.
Baseline to Month Three Changes in Insulin Sensitivity: Average Group Improvements Despite Varied Individual Responses.
Each bar represents insulin sensitivity improvements for participating individuals. A. By intervention group. CR = Caloric restriction; CR+EX = Caloric restriction with exercise; Control = Healthy weight maintenance diet; LCD = Liquid calorie diet B. Intervention groups combined.
Figure 4.
Correlation Between Fasting to Postprandial Component Changes and Predicted SI Change Over Time.
As described in Methods, fasting and postprandial concentrations of amino acids and acylcarnitines were measured at baseline, three months, and six months, and fasting to postprandial components were generated. SI was determined from insulin and glucose concentrations measured during a frequently sampled intravenous tolerance test at each of baseline, three, and six months. Linear models were used to relate time varying concentrations of fasting to postprandial amino acid and acylcarnitine component to time varying insulin sensitivity (SI). Scatter plots depict the relation between fasting to postprandial component scores and predicted SI. A. Relation between Acylcarnitines (AC) Fasting to Postprandial Component Scores and Predicted SI Over Time. Since postprandial AC concentrations are larger than fasting, more negative fasting to postprandial differences represent more metabolic flexibility. B. Relation between Amino Acid (AA) Fasting to Postprandial Component Scores and Predicted SI Over Time.
Figure 5.
Preprandial and postprandial concentrations of acylcarnitines in response to caloric restriction (CR).
Baseline and three month acylcarnitine concentrations are shown for both fasting (preprandial) and postprandial assessments. The six acylcarnitines that had the largest loadings on the acylcarnitine factor (see Table 1) are shown.
Figure 6.
Preprandial and postprandial concentrations of amino acids for those with the highest and lowest insulin sensitivity changes.
Baseline and three month amino acids concentrations are shown for both fasting (preprandial) and postprandial assessments. The five amino acids that had the largest loadings on the amino acid factor (see Table 1) are shown. Leu/Ile = leucine/isoleucine, Phe = phenylalanine, Met = Methionine, His = Histidine, Val = Valine.