Association of postoperative dietary macronutrient content and quality with total weight loss and fat-free mass loss at midterm after sleeve gastrectomy

OBJECTIVES

This study aimed to investigate the associations of macronutrient quantities and qualities with percentage total weight loss and percentage of fat-free mass loss relative to total weight loss in adults undergoing sleeve gastrectomy.

METHODS

This cross-sectional study included 146 patients on postoperative time since sleeve gastrectomy of 2 to 4 y. Diet was assessed using a food frequency questionnaire. Macronutrient quality index, carbohydrate quality index, fat quality index, and healthy plate protein quality index were calculated. The associations of dietary variables with percentage total weight loss and percentage of fat-free mass loss relative to total weight loss were determined using linear regression. Logistic regression was used to estimate the odds of non-response (percentage total weight loss < 25%) and excessive fat-free mass loss (percentage of fat-free mass loss relative to total weight loss > 28%) based on dietary intakes.

RESULTS

Forty-six (31.5%) were non-responders, and 49 (33.6%) experienced excessive fat-free mass loss. The fully adjusted model showed a 0.75 decrease in percentage total weight loss per 5% carbohydrate increase (95% CI, -1.45 to -0.05). The odds of non-response were 53% lower per 5% increase in protein (95% CI, 0.23-0.94). Each 5-g higher intake of fat was associated with 0.29 higher percentage of fat-free mass loss relative to total weight loss (95% CI, 0.03-0.55). The odds of excessive fat-free mass loss were reduced by 5% per gram of fiber intake (95% CI, 0.90-0.99). Each 5% increment in energy intake from protein that was isocalorically substituted for either carbohydrate or fat was associated with lower odds of nonresponse. Macronutrient quality indices had no significant associations.

CONCLUSIONS

Adherence to a high-protein, high-fiber diet after sleeve gastrectomy may enhance surgical success by improving total weight loss and preventing excessive fat-free mass loss.

Macronutrient quality and the incidence of metabolically unhealthy phenotypes in adults with normal weight and overweight/obesity

OBJECTIVE

We aimed to investigate the associations of macronutrient quality indices with the incident metabolically unhealthy normal weight (MUNW) and metabolically unhealthy overweight/obesity (MUO) phenotypes.

METHODS

This prospective study included 512 metabolically healthy normal weight and 787 metabolically healthy overweight/obese adults from the third study examination of the Tehran Lipid and Glucose Study. The participants were followed through the sixth study examination. Diet was measured with a food frequency questionnaire. The macronutrient quality index (MQI), carbohydrate quality index (CQI), fat quality index (FQI), and healthy plate quality index (HPPQI) were calculated. Hazard ratio (HR) and 95 % confidence interval (95 % CI) were estimated for incident unhealthy phenotypes using Cox regression.

RESULTS

After controlling all possible confounding factors, a one-point higher HPPQI was linked to a 28 % lower risk of MUNW (HR = 0.72; 95 % CI = 0.59, 0.87). Compared to the lowest quartile, the incident MUNW was also lower in the two last quartiles of the HPPQI. A one-unit increase in MQI was associated with a 5 % lower incident MUO (HR = 0.95; 95 % CI = 0.92, 0.99). The incident MUO was also higher for the highest compared to the lowest MQI quartile. In quartiles 2-4 of the HPPQI, incident MUO was lower with respective HRs (95 % CI) of 0.71 (0.54, 0.93), 0.60 (0.45, 0.80), and 0.66 (0.50, 0.86) in the fully-adjusted model.

CONCLUSIONS

A higher overall macronutrient quality was independently associated with a lower incident MUO. A higher dietary protein quality was related to a lower risk for MUNW and MUO.

Fat Quality Index and Risk of Cardiovascular Disease in the Sun Project

OBJECTIVES

To examine the association between a dietary fat quality index (FQI), and the risk of incident cardiovascular events or deaths in the Seguimiento Universidad de Navarra (SUN) cohort.

DESIGN

Longitudinal analysis during 10.1 years of median follow-up. Cox models were used to estimate adjusted hazard ratios (HR) of incident cardiovascular diseases (CVD) according to tertiles of FQI and of different fat subtypes.

SETTING

University of Navarra, Spain.

PARTICIPANTS

19,341 middle-aged adults.

MEASUREMENTS

Fat intake was measured with a validated food-frequency questionnaire. The FQI was calculated according to the ratio: (monounsaturated+polyunsaturated) / (saturated+trans fatty acids).

RESULTS

We observed 140 incident cases of CVD. No association was found for FQI (HR=0.94, 95 %CI 0.61-1.47 for the highest vs the lowest tertile, p for trend=0.884). No significant associations were found for different dietary fat subtypes on CVD risk. The results suggest no clear association between a higher FQI and a higher amount of energy from fat and incidence of CVD (p for interaction: 0.259 and p for trend only among participants with a percentage of energy from fat ≥35% of total energy: 0.272).

CONCLUSION

In this Mediterranean cohort, the FQI was not associated with cardiovascular events. A "heart-healthy diet" should focus its attention on dietary fat sources and should use an overall dietary pattern approach, rather than limiting the focus on fat subtypes. More research is needed to validate dietary advice on specific fatty acids intake or saturated fatty acids replacements for reducing CVD risk.