Endurance Training Counteracts the High-Fat Diet-Induced Profiling Changes of ω-3 Polyunsaturated Fatty Acids in Skeletal Muscle of Middle-Aged Rats

We hypothesized that variation in dietary fatty acid composition in rats fed a high-fat diet had tissue-specific effects on glucose uptake sufficient to maintain normal glucose tolerance. Rats were fed one of three diets for 3 wk. The isocaloric high-fat-mixed oil (HF-mixed) diet and the high-fat-safflower oil (HF-saff) diet both provided 60% kcal fat, but fat composition differed [HF-mixed = saturated, polyunsaturated (n-3 and n-6), and monounsaturated fatty acids; HF-saff = polyunsaturated fatty acids (mainly n-6)]. The control diet was high carbohydrate (HCHO, 10% kcal fat). Insulin-stimulated 3- O-methylglucose uptake into perfused hindlimb muscles was reduced in rats fed HF-saff and HF-mixed diets compared with those fed HCHO diet ( P< 0.02). Basal uptake increased in HF-saff- and HF-mixed-fed rats vs. HCHO-fed rats ( P < 0.04). In adipocytes, HF-saff feeding decreased 2-deoxyglucose uptake vs. HF-mixed feeding and HCHO feeding ( P< 0.05), but 2-deoxyglucose uptake in HF-mixed-fed rats did not differ from that in HCHO-fed rats ( P> 0.05). Glucose tolerance was significantly reduced in HF-saff-fed rats but was unaffected by the HF-mixed diet. Therefore, in skeletal muscle of rats, 1) feeding a diet high in fat induces a reduction in insulin-stimulated glucose uptake but 2) provides an increase in basal glucose uptake. In contrast, 3) in adipocytes, insulin-stimulated glucose transport is reduced only when the high-fat diet is high in n-6 polyunsaturated fatty acids but not when fat comes from these mixed sources. Glucose intolerance becomes evident when insulin resistance is seen in multiple tissues.

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DHA-enriched phospholipids from large yellow croaker roe regulate lipid metabolic disorders and gut microbiota imbalance on SD rats with a high-fat diet

Food & Function ◽

10.1039/d1fo00747e ◽

2021 ◽

Author(s):

Xiaodan Lu ◽

Rongbin Zhong ◽

Ling Hu ◽

Luyao Huang ◽

Lijiao Chen ◽

...

Keyword(s):

Fatty Acids ◽

Docosahexaenoic Acid ◽

Gut Microbiota ◽

Polyunsaturated Fatty Acids ◽

High Fat Diet ◽

Nutritional Value ◽

Metabolic Disorders ◽

Large Yellow Croaker ◽

High Fat ◽

Sd Rats

Abstract Large yellow croaker roe phospholipids (LYCRPLs) has great nutritional value because of containing rich docosahexaenoic acid (DHA), which is a kind of n-3 polyunsaturated fatty acids (n-3 PUFAs). In...

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High ratio of ω-3/ω-6 polyunsaturated fatty acids targets mTORC1 to prevent high-fat diet-induced metabolic syndrome and mitochondrial dysfunction in mice

The Journal of Nutritional Biochemistry ◽

10.1016/j.jnutbio.2019.108330 ◽

2020 ◽

Vol 79 ◽

pp. 108330 ◽

Cited By ~ 4

Author(s):

Run Liu ◽

Lei Chen ◽

Yan Wang ◽

Guanfei Zhang ◽

Ying Cheng ◽

...

Keyword(s):

Metabolic Syndrome ◽

Fatty Acids ◽

Polyunsaturated Fatty Acids ◽

Mitochondrial Dysfunction ◽

High Fat Diet ◽

High Ratio ◽

High Fat

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Saturated, but not n-6 polyunsaturated, fatty acids induce insulin resistance: role of intramuscular accumulation of lipid metabolites

Journal of Applied Physiology ◽

10.1152/japplphysiol.01438.2005 ◽

2006 ◽

Vol 100 (5) ◽

pp. 1467-1474 ◽

Cited By ~ 203

Author(s):

Jong Sam Lee ◽

Srijan K. Pinnamaneni ◽

Su Ju Eo ◽

In Ho Cho ◽

Jae Hwan Pyo ◽

...

Keyword(s):

Insulin Resistance ◽

Skeletal Muscle ◽

Fatty Acids ◽

Insulin Sensitivity ◽

Polyunsaturated Fatty Acids ◽

Glucose Uptake ◽

High Fat ◽

Insulin Resistant ◽

L6 Myotubes ◽

Lipid Metabolites

Consumption of a Western diet rich in saturated fats is associated with obesity and insulin resistance. In some insulin-resistant phenotypes this is associated with accumulation of skeletal muscle fatty acids. We examined the effects of diets high in saturated fatty acids (Sat) or n-6 polyunsaturated fatty acids (PUFA) on skeletal muscle fatty acid metabolite accumulation and whole-body insulin sensitivity. Male Sprague-Dawley rats were fed a chow diet (16% calories from fat, Con) or a diet high (53%) in Sat or PUFA for 8 wk. Insulin sensitivity was assessed by fasting plasma glucose and insulin and glucose tolerance via an oral glucose tolerance test. Muscle ceramide and diacylglycerol (DAG) levels and triacylglycerol (TAG) fatty acids were also measured. Both high-fat diets increased plasma free fatty acid levels by 30%. Compared with Con, Sat-fed rats were insulin resistant, whereas PUFA-treated rats showed improved insulin sensitivity. Sat caused a 125% increase in muscle DAG and a small increase in TAG. Although PUFA also resulted in a small increase in DAG, the excess fatty acids were primarily directed toward TAG storage (105% above Con). Ceramide content was unaffected by either high-fat diet. To examine the effects of fatty acids on cellular lipid storage and glucose uptake in vitro, rat L6 myotubes were incubated for 5 h with saturated and polyunsaturated fatty acids. After treatment of L6 myotubes with palmitate (C16:0), the ceramide and DAG content were increased by two- and fivefold, respectively, concomitant with reduced insulin-stimulated glucose uptake. In contrast, treatment of these cells with linoleate (C18:2) did not alter DAG, ceramide levels, and glucose uptake compared with controls (no added fatty acids). Both 16:0 and 18:2 treatments increased myotube TAG levels (C18:2 vs. C16:0, P < 0.05). These results indicate that increasing dietary Sat induces insulin resistance with concomitant increases in muscle DAG. Diets rich in n-6 PUFA appear to prevent insulin resistance by directing fat into TAG, rather than other lipid metabolites.

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A randomised four-intervention crossover study investigating the effect of carbohydrates on daytime profiles of insulin, glucose, non-esterified fatty acids and triacylglycerols in middle-aged men

British Journal Of Nutrition ◽

10.1079/bjn2002769 ◽

2003 ◽

Vol 89 (2) ◽

pp. 207-218 ◽

Cited By ~ 94

Author(s):

Audrey E. Brynes ◽

C. Mark Edwards ◽

Mohammed A. Ghatei ◽

Anne Dornhorst ◽

Linda M. Morgan ◽

...

Keyword(s):

Risk Factors ◽

Fatty Acids ◽

High Fat Diet ◽

Assessment Model ◽

High Fat ◽

Middle Aged ◽

High Carbohydrate ◽

Esterified Fatty Acids ◽

Sucrose Diet ◽

Postprandial Insulin

Postprandial concentrations of glucose, insulin and triacylglycerols (TG) correlate to risk for CHD. Carbohydrates affect many metabolites that could have a potential effect on cardiovascular risk factors. The objective of the present study was to examine, using a randomised prospective study, the acute (day 1) and ad libitum medium-term (day 24) effects of four diets: a high-fat diet (HIGH-FAT; 50 % fat, >34 % monounsaturated fatty acids); a low-glycaemic index (GI) diet (LOW-GI; high-carbohydrate, low-GI); a high-sucrose diet (SUCROSE; high carbohydrate increase of 90 g sucrose/d); a high-GI diet (HIGH-GI; high-carbohydrate, high-GI). Daytime profiles (8 h) (breakfast, lunch and tea) of lipid and carbohydrate metabolism were completed during day 1 and day 24. Seventeen middle-aged men with one or more cardiac risk factors completed the study. There was no change from day 1 or between diets in fasting glucose, lipids or homeostatic assessment model (HOMA) on day 24. The HIGH-FAT compared with the three high-carbohydrate diets was associated with lower postprandial insulin and glucose but higher postprandial TG and non-esterified fatty acids (NEFA). There was a significant increase in the 6 h (15.00 hours) TG concentration (day 1, 2·6 (SEM 0·3) MMOL/L v. DAY 24, 3·3 (sem 0·3) mmol/l; P<0·01) on the SUCROSE diet. Postprandial HOMA (i.e. incremental area under the curve (IAUC) glucose (mmol/l per min)×IAUC insulin/22·5 (mU/l per min)) median changes from day 1 to day 24 were −61, −43, −20 and +31 % for the HIGH-FAT, LOW-GI, SUCROSE and HIGH-GI diets respectively. The HIGH-GI percentage change was significantly different from the other three diets (P<0·001). Despite being advised to maintain an identical energy intake there was a significant weight change (−0·27 (sem 0·3) kg; P<0·02) on the LOW-GI diet compared with the SUCROSE diet (+0·84 (sem 0·3) kg). In conclusion the HIGH-FAT diet had a beneficial effect on postprandial glucose and insulin over time but it was associated with higher postprandial concentrations of TG and NEFA. Conversely the HIGH-GI diet appeared to increase postprandial insulin resistance over the study period.

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