The in vivo effect of elevated free fatty acids (FFA) on β-cell function in humans remains extremely controversial. We examined, in healthy young men, the acute (90 min) and chronic (48 h) effects of an approximately twofold elevation of plasma FFA vs. control on glucose-stimulated insulin secretion (GSIS). GSIS was studied in response to a graded intravenous glucose infusion (peak plasma glucose, ∼10 mmol/l, n = 8) and a two-step hyperglycemic clamp (10 and 20 mmol/l, n = 8). In the acute studies, GSIS was significantly higher, insulin sensitivity index (SI) was lower, and disposition index (DI = insulin sensitivity × insulin secretion) was unchanged with elevated FFA vs. control [2-step clamp: DI = 8.9 ± 1.4 × 10−3l2 ⋅ kg−1 ⋅ min−2in control vs. 10.0 ± 1.9 × 10−3l2 ⋅ kg−1 ⋅ min−2with high FFA, P = nonsignificant (NS)]. In the chronic studies, there was no difference in absolute GSIS between control and high FFA studies, but there was a reduction in SI and a loss of the expected compensatory increase in insulin secretion as assessed by the DI (2-step clamp: DI = 10.0 ± 1.2 × 10−3l2 ⋅ kg−1 ⋅ min−2in control vs. 6.1 ± 0.7 × 10−3l2 ⋅ kg−1 ⋅ min−2with high FFA, P = 0.01). In summary, 1) acute and chronic FFA elevation induces insulin resistance; 2) with acute FFA elevation, this insulin resistance is precisely countered by an FFA-induced increase in insulin secretion, such that DI does not change; and 3) chronic FFA elevation disables this β-cell compensation.
Objective: To evaluate the validity (study 1) and the reproducibility (study 2) of an intervieweradministered food frequency questionnaire (FFQ). Method:The FFQ was designed at Laval University and contains 91 items and 33 subquestions. Study 1: The FFQ was compared against a 3-day food record (2 week-days and 1 weekend-day), at week 0, 6 and 12 of a nutritional intervention. Study 2: In order to evaluate the reproducibility of the FFQ, 2 registered dietitians administered the FFQ 4-weeks apart among subjects who were not part of the nutritional intervention. Results: Study 1:Mean values for intake of most nutrients assessed by the FFQ and by the 3-day food record were not statistically different. Energy-adjusted correlation coefficients for major macronutrients ranged from 0.36 for proteins to 0.60 for carbohydrates (p ≤ 0.01). Agreement analysis revealed that on average, 35% of the subjects were classified in the same quartile when nutrients were assessed by either the 3-day food record or the FFQ. Study 2: Significant associations were observed between dietary measurements derived from the two FFQs administered 4 weeks apart. Correlation coefficients for the reproducibility of macronutrients ranged from 0.66 for carbohydrates to 0.83 for lipids after energy adjustment. On average, 46% of the subjects were classified in the same quartile when nutrient intakes were assessed by either FFQ. Conclusion:These data indicated that the FFQ developed has a good validity and is reproducible.
Background:The intake of trans fatty acids (TFA) from industrially hydrogenated vegetable oils (iTFA) is known to have a deleterious effect on cardiovascular health, the effects of TFA from ruminants (rTFA) are virtually unknown. Objective: The purpose of the present study was to compare the effects of rTFA and iTFA on plasma LDL concentrations and other cardiovascular disease risk factors in healthy subjects. Design: In a double-blind, randomized crossover controlled study, 38 healthy men were fed each of 4 experimental isoenergetic diets lasting 4 wk each. The 4 diets were high in rTFA (10.2 g/2500 kcal), moderate in rTFA (4.2 g/2500 kcal), high in iTFA (10.2 g/2500 kcal), and low in TFA from any source (2.2 g/2500 kcal) (control diet). Results: Plasma LDL-cholesterol concentrations were significantly higher after the high-rTFA diet than after the control (P ҃ 0.03) or the moderate-rTFA (P ҃ 0.002) diet. Plasma LDL-cholesterol concentrations also were significantly (P ҃ 0.02) higher after the iTFA diet than after the moderate-rTFA diet. Plasma HDL-cholesterol concentrations were significantly (P ҃ 0.02) lower after the highrTFA diet than after the moderate-rTFA diet. Finally, all risk factors were comparable between the control and the moderate-rTFA diets. Conclusions: These results suggest that, whereas a high dietary intake of TFA from ruminants may adversely affect cholesterol homeostasis, moderate intakes of rTFA that are well above the upper limit of current human consumption have neutral effects on plasma lipids and other cardiovascular disease risk factors.Am J Clin Nutr 2008;87:593-9.
The worldwide increase in the prevalence and incidence of type 2 diabetes represents a tremendous challenge for the Canadian health care system, especially if we consider that this phenomenon may largely be explained by the epidemic of obesity. However, despite the well-recognized increased morbidity and mortality associated with an elevated body weight, there is now more and more evidence highlighting the importance of intra-abdominal adipose tissue (visceral adipose tissue) as the fat depot conveying the greatest risk of metabolic complications. In this regard, body fat distribution, especially visceral adipose tissue accumulation, has been found to be a key correlate of a cluster of diabetogenic, atherogenic, prothrombotic and inflammatory metabolic abnormalities now often referred to as the metabolic syndrome. This dysmetabolic profile is predictive of a substantially increased risk of coronary artery disease (CAD) even in the absence of hyperglycemia, elevated low-density lipoprotein cholesterol or hypertension. For instance, some features of the metabolic syndrome (hyperinsulinemia, elevated apolipoprotein B and small low-density lipoprotein particles -the so-called atherogenic metabolic triad) have been associated with a more than 20-fold increase in the risk of ischemic heart disease in middle-aged men enrolled in the Quebec Cardiovascular Study. This cluster of metabolic complications has also been found to be predictive of a substantially increased risk of CAD beyond the presence of traditional risk factors. These results emphasize the importance of taking into account in daily clinical practice the presence of metabolic complications associated with abdominal obesity together with traditional risk factors to properly evaluate the cardiovascular risk profile of patients. From a risk assessment standpoint, on the basis of additional work conducted by several groups, there is now evidence that the simultaneous presence of an elevated waist circumference and fasting triglyceride levels (a condition that has been described as hypertriglyceridemic waist) may represent a relevant first-step approach to identify a subgroup of individuals at higher risk of being carriers of the features of the metabolic syndrome. Moreover, a moderate weight loss in initially abdominally obese patients is associated with a selective mobilization of visceral adipose tissue, leading to improvements in the metabolic risk profile predictive of a reduced risk of CAD and type 2 diabetes. In conclusion, hypertriglyceridemic waist as a marker of visceral obesity and related metabolic abnormalities is a useful and practical clinical phenotype to screen persons at risk for CAD and type 2 diabetes. La hausse mondiale de prévalence et d'incidence de diabète de type 2 constitue un énorme problème pour le système de santé canadien, notamment lorsqu'on considère que ce phénomène s'explique en grande partie par l'épidémie d'obésité. Cependant, malgré l'augmentation bien connue de la morbidité et de la mortalité associée à un poids corporel éle...
Background The impact that the coronavirus disease 2019 (COVID-19)–related early lockdown has had on dietary habits of the population and on food insecurity is unknown. Objective The aim of this study was to document the change in diet quality and in food insecurity observed during the COVID-19–related early lockdown. We hypothesized that the lockdown was associated with a deterioration in overall diet quality and an increase in food insecurity. Methods Data are from a COVID-19 subsample of NutriQuébec, a web-based cohort destined to study temporal changes in dietary habits among adults in Quebec, Canada. Participants completed questionnaires before (between June 2019 and February 2020) and during (April to May 2020) early lockdown, including a validated web-based 24-h recall ( n = 853) and a questionnaire on food security ( n = 922). Primary study outcomes were temporal changes in diet quality measured by the Healthy Eating Index (HEI)–2015 and in the prevalence of food insecurity. Results There was a small increase in the HEI-2015 during the COVID-19 early lockdown compared with baseline (+1.1 points; 95% CI: 0.6, 1.5), mostly due to small improvements in the intakes of whole grains, greens and beans, refined grains, total vegetables, total dairy, seafood and plant proteins, added sugar, and total protein subscores of the HEI-2015. Exploratory analyses suggested that individuals aged 18–29 y (+3.6 points; 95% CI: 2.4, 4.7), participants with lower education (+1.9 points; 95% CI: 1.3, 2.6), or with obesity (+3.8 points; 95% CI: 2.7, 4.8) showed particularly important increases in the HEI-2015. The prevalence of food insecurity was reduced from 3.8% at baseline to 1.0% during the early lockdown (prevalence ratio = 0.27; 95% CI: 0.08, 0.94). Conclusions Contrary to our hypotheses, diet quality has slightly improved and prevalence of food insecurity was reduced in this sample of adults from Quebec during the COVID-19–related early lockdown. These results may be generalizable only to relatively healthy populations.
Consumption of dietary trans FAs is associated with a deleterious increase in small, dense LDL, which further reinforces the importance of promoting diets low in trans FAs to favorably affect the lipoprotein profile.
Thus, consuming MedDiet even in the absence of weight loss significantly reduces inflammation. However, the degree of waist circumference reduction with weight loss magnifies the impact of the MedDiet on other markers of inflammation associated with MetS in men.
The purpose of this study was to evaluate the impact of adopting a Mediterranean diet on dietary cost and energy density in free-living conditions. The 12-wk nutritional intervention consisted of 2 group courses and 7 individual sessions with a dietician in a sample of 73 healthy women. To evaluate the dietary response to the nutritional intervention, a registered dietician administered a FFQ at 0, 6, 12, and 24 wk. Total daily dietary cost was calculated using a price list including all items from the FFQ. Our findings indicated that daily energy cost evaluated at wk 12 vs. wk 0 [1046 +/- 217 vs. 967 +/- 192 kJ/Canadian dollars (CAN$), respectively, P = 0.18] and total daily dietary cost (8.61 +/- 2.13 vs. 8.75 +/- 2.50 CAN$/d per participant, respectively, P = 0.58) did not change. Total daily energy density at wk 12 decreased compared with wk 0 (2.56 +/- 0.76 vs. 2.20 +/- 0.67 kJ/g; P < 0.0001). Adherence to the Mediterranean diet led to increased cost related to vegetables, fruits, legumes, nuts and seeds, canola/olive oil, whole grains, poultry, and fish (P < or = 0.01) and to reduced dietary cost for red meat, refined grains, desserts and sweets, and fast food (P < or = 0.008). In conclusion, these data suggest that adherence to a nutritional intervention program promoting the Mediterranean food pattern is not associated with increased daily dietary cost or energy cost but led to a reduction in energy density. Consequently, increased cost should not be considered a barrier to the promotion and adoption of a Mediterranean diet.
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