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As Peat has routinely emphasized, the macro-nutrient composition of the diet makes a profound impact on the state of the organism. Moreover, Peat goes further to advocate select foods that favor certain compositions; restricting select amino acids like Methionine (abundant in red meat) being one of them. As such, the importance of diet on Insulin and or subsequent Resistance must gain attention.
The following studies (from a multitude on PubMed) provide weight to Peats notion that High-Carb diets do not negatively impact insulin sensitivity, and are more likely preferable. Going further, insulin sensitivity can be improved when select carbohydrates are consumed, whilst high-fat diets impact insulin sensitivity negatively.
It follows that low-glycemic carbohydrates, including fruits and (fibrous starches), are expressed throughout several studies as the basis of the diet.
The role of carbohydrates in insulin resistance, 2001
The role of carbohydrates in insulin resistance. - PubMed - NCBI
Insulin resistance is a metabolic disorder that is increasing worldwide and is associated with some of the most common diseases affecting modern societies including diabetes, hypertension, obesity and coronary heart disease. Although pharmacologic approaches to managing insulin resistance are being advocated by some, public health approaches involving changes in diet and physical activity are attractive because of their lower cost and risk. We briefly summarize some new information on the mechanisms that mediate insulin's many biological actions and examine the effects of dietary carbohydrates on insulin sensitivity. Specifically, we summarize some of the information available on the effects of simple sugars, complex carbohydrates including fiber, slowly digested starch and the general concept of glycemic index. The available data support the idea that consumption of diets high in total carbohydrate does not adversely affect insulin sensitivity compared with high fat diets.
Insulin resistance, low-fat diets, and low-carbohydrate diets: time to test new menus.
Insulin resistance, low-fat diets, and low-carbohydrate diets: time to test new menus. - PubMed - NCBI
PURPOSE OF REVIEW:
Insulin resistance increases the risk of cardiovascular disease and diabetes, and the risk of cardiovascular disease increases further once diabetes has developed. As insulin resistance is a precursor to diabetes, it is critically important to identify cost-effective means, such as dietary changes, by which to reduce insulin resistance. The purpose of this review is to evaluate recent findings concerning dietary composition and insulin resistance, with particular focus on low-fat diets compared with the currently popular low-carbohydrate diets.
RECENT FINDINGS:
Recent findings indicate little support for the value of low-carbohydrate diets as therapies for insulin resistance. In contrast, the limited data available suggest that the higher fat content of typical low-carbohydrate diets may exacerbate insulin resistance in the long term. Preliminary data indicate that proteins from different sources may have differing effects on insulin resistance. Preliminary data also suggest the potential value of whole grains, fruits and vegetables in therapeutic diets to reduce insulin resistance.
SUMMARY:
Current evidence supports the inclusion of whole grains, fruits and vegetables, and lean sources of animal proteins including low-fat dairy products in dietary therapies for insulin resistance. Those who wish to follow a low-carbohydrate diet should be encouraged to follow a new menu low in fat, and with most of the protein derived from plant sources.
A high-fat, ketogenic diet causes hepatic insulin resistance in mice, despite increasing energy expenditure and preventing weight gain
A high-fat, ketogenic diet causes hepatic insulin resistance in mice, despite increasing energy expenditure and preventing weight gain
In conclusion, the present study shows that a high-fat KD causes hepatic insulin resistance in mice, which can be attributed to an increase in hepatic DAG content, leading to PKCε activation and subsequent impaired insulin signaling. Moreover, this study found that a KD increases energy expenditure, which results in weight loss. Given the widespread use of KD in the treatment of obesity and the role of NAFLD and hepatic insulin resistance in promoting type 2 diabetes, these results may have important clinical implications, as obese patients on such diets could lose weight but develop NAFLD and hepatic insulin resistance.
Consumption of a High-Fat Diet Induces Central Insulin Resistance Independent of Adiposity
Consumption of a High-Fat Diet Induces Central Insulin Resistance Independent of Adiposity
These studies also assessed whether a short period of prior access to a HF diet is sufficient for central insulin resistance to develop; importantly, 72-hrs consumption of a HF diet was found to be sufficient to reduce central insulin sensitivity, independent of statistically significant changes in body weight or body adiposity
Previous studies have demonstrated that a reduction of dietary fat is able to improve peripheral insulin sensitivity in humans (59, 60). In rats, reducing dietary fat from 40% to 30% of total energy rapidly restored peripheral insulin sensitivity (34). Hence, the present findings are consistent with the more general hypothesis that dietary fat induces both central and peripheral insulin resistance, and that this is independent of body adiposity.
Effects of an ad libitum, high carbohydrate diet and aerobic exercise training on insulin action and muscle metabolism in older men and women.
Effects of an ad libitum, high carbohydrate diet and aerobic exercise training on insulin action and muscle metabolism in older men and women. - PubMed - NCBI
BACKGROUND:
Previous studies have demonstrated that aerobic exercise training and weight loss have independent effects on insulin-stimulated glucose disposal (ISGD). We hypothesized that ad libitum consumption of a high-carbohydrate diet would result in weight loss and improved ISGD, and that aerobic exercise training would facilitate greater improvements in ISGD compared with diet alone.
METHODS:
Older participants (13 women, 9 men; age = 66 +/- 1 year) with impaired glucose tolerance were randomly assigned to an ad libitum diet alone (18% fat, 19% protein, 63% carbohydrate) or this diet plus aerobic exercise training (4 d/wk, 45 min/d, 80% VO(2peak)) for 12 weeks. ISGD, abdominal fat distribution, muscle glycogen, and glycogen synthase activity were assessed pre- and postintervention.
RESULTS:
Consumption of the diet resulted in significant weight loss and an improvement in ISGD. Consumption of the diet plus exercise training also resulted in weight loss and increased ISGD, but results were not significantly different from those in the diet-alone group. Mean abdominal visceral and subcutaneous adipose tissue cross-sectional areas were smaller postintervention compared to baseline with no difference between groups. Exercise training and consumption of the diet increased muscle glycogen content (344.7 +/- 21.3 to 616.7 +/- 34.4 micromol.g(-1)) and decreased glycogen synthase activity (0.21 +/- 0.02 to 0.13 +/- 0.01) compared to the diet alone.
CONCLUSIONS:
These results demonstrate that consumption of an ad libitum, high-carbohydrate diet alone or in combination with aerobic exercise training results in weight loss and improved insulin sensitivity. Furthermore, exercise combined with this diet appears to limit additional increases in insulin sensitivity due to muscle glycogen supercompensation with a concomitant adaptive response of glycogen synthase.
Meat Intake and Insulin Resistance in Women without Type 2 Diabetes
In conclusion, it appears that meat intake, particularly red and processed meats, is associated with higher levels of insulin resistance in middle-aged women without type 2 diabetes. Among the many potential confounders examined in this study, BMI and body fat percentage influenced the association significantly. Consequently, both a lower meat intake and lower levels of body fat appear important in reducing the likelihood of insulin resistance, especially in this sample. Consumption of very lean meats (VLM) does not seem to play a role in insulin resistance. To decrease the likelihood of insulin resistance, prudence in the amount and type of meat consumed may be helpful.
The following studies (from a multitude on PubMed) provide weight to Peats notion that High-Carb diets do not negatively impact insulin sensitivity, and are more likely preferable. Going further, insulin sensitivity can be improved when select carbohydrates are consumed, whilst high-fat diets impact insulin sensitivity negatively.
It follows that low-glycemic carbohydrates, including fruits and (fibrous starches), are expressed throughout several studies as the basis of the diet.
The role of carbohydrates in insulin resistance, 2001
The role of carbohydrates in insulin resistance. - PubMed - NCBI
Insulin resistance is a metabolic disorder that is increasing worldwide and is associated with some of the most common diseases affecting modern societies including diabetes, hypertension, obesity and coronary heart disease. Although pharmacologic approaches to managing insulin resistance are being advocated by some, public health approaches involving changes in diet and physical activity are attractive because of their lower cost and risk. We briefly summarize some new information on the mechanisms that mediate insulin's many biological actions and examine the effects of dietary carbohydrates on insulin sensitivity. Specifically, we summarize some of the information available on the effects of simple sugars, complex carbohydrates including fiber, slowly digested starch and the general concept of glycemic index. The available data support the idea that consumption of diets high in total carbohydrate does not adversely affect insulin sensitivity compared with high fat diets.
Insulin resistance, low-fat diets, and low-carbohydrate diets: time to test new menus.
Insulin resistance, low-fat diets, and low-carbohydrate diets: time to test new menus. - PubMed - NCBI
PURPOSE OF REVIEW:
Insulin resistance increases the risk of cardiovascular disease and diabetes, and the risk of cardiovascular disease increases further once diabetes has developed. As insulin resistance is a precursor to diabetes, it is critically important to identify cost-effective means, such as dietary changes, by which to reduce insulin resistance. The purpose of this review is to evaluate recent findings concerning dietary composition and insulin resistance, with particular focus on low-fat diets compared with the currently popular low-carbohydrate diets.
RECENT FINDINGS:
Recent findings indicate little support for the value of low-carbohydrate diets as therapies for insulin resistance. In contrast, the limited data available suggest that the higher fat content of typical low-carbohydrate diets may exacerbate insulin resistance in the long term. Preliminary data indicate that proteins from different sources may have differing effects on insulin resistance. Preliminary data also suggest the potential value of whole grains, fruits and vegetables in therapeutic diets to reduce insulin resistance.
SUMMARY:
Current evidence supports the inclusion of whole grains, fruits and vegetables, and lean sources of animal proteins including low-fat dairy products in dietary therapies for insulin resistance. Those who wish to follow a low-carbohydrate diet should be encouraged to follow a new menu low in fat, and with most of the protein derived from plant sources.
A high-fat, ketogenic diet causes hepatic insulin resistance in mice, despite increasing energy expenditure and preventing weight gain
A high-fat, ketogenic diet causes hepatic insulin resistance in mice, despite increasing energy expenditure and preventing weight gain
In conclusion, the present study shows that a high-fat KD causes hepatic insulin resistance in mice, which can be attributed to an increase in hepatic DAG content, leading to PKCε activation and subsequent impaired insulin signaling. Moreover, this study found that a KD increases energy expenditure, which results in weight loss. Given the widespread use of KD in the treatment of obesity and the role of NAFLD and hepatic insulin resistance in promoting type 2 diabetes, these results may have important clinical implications, as obese patients on such diets could lose weight but develop NAFLD and hepatic insulin resistance.
Consumption of a High-Fat Diet Induces Central Insulin Resistance Independent of Adiposity
Consumption of a High-Fat Diet Induces Central Insulin Resistance Independent of Adiposity
These studies also assessed whether a short period of prior access to a HF diet is sufficient for central insulin resistance to develop; importantly, 72-hrs consumption of a HF diet was found to be sufficient to reduce central insulin sensitivity, independent of statistically significant changes in body weight or body adiposity
Previous studies have demonstrated that a reduction of dietary fat is able to improve peripheral insulin sensitivity in humans (59, 60). In rats, reducing dietary fat from 40% to 30% of total energy rapidly restored peripheral insulin sensitivity (34). Hence, the present findings are consistent with the more general hypothesis that dietary fat induces both central and peripheral insulin resistance, and that this is independent of body adiposity.
Effects of an ad libitum, high carbohydrate diet and aerobic exercise training on insulin action and muscle metabolism in older men and women.
Effects of an ad libitum, high carbohydrate diet and aerobic exercise training on insulin action and muscle metabolism in older men and women. - PubMed - NCBI
BACKGROUND:
Previous studies have demonstrated that aerobic exercise training and weight loss have independent effects on insulin-stimulated glucose disposal (ISGD). We hypothesized that ad libitum consumption of a high-carbohydrate diet would result in weight loss and improved ISGD, and that aerobic exercise training would facilitate greater improvements in ISGD compared with diet alone.
METHODS:
Older participants (13 women, 9 men; age = 66 +/- 1 year) with impaired glucose tolerance were randomly assigned to an ad libitum diet alone (18% fat, 19% protein, 63% carbohydrate) or this diet plus aerobic exercise training (4 d/wk, 45 min/d, 80% VO(2peak)) for 12 weeks. ISGD, abdominal fat distribution, muscle glycogen, and glycogen synthase activity were assessed pre- and postintervention.
RESULTS:
Consumption of the diet resulted in significant weight loss and an improvement in ISGD. Consumption of the diet plus exercise training also resulted in weight loss and increased ISGD, but results were not significantly different from those in the diet-alone group. Mean abdominal visceral and subcutaneous adipose tissue cross-sectional areas were smaller postintervention compared to baseline with no difference between groups. Exercise training and consumption of the diet increased muscle glycogen content (344.7 +/- 21.3 to 616.7 +/- 34.4 micromol.g(-1)) and decreased glycogen synthase activity (0.21 +/- 0.02 to 0.13 +/- 0.01) compared to the diet alone.
CONCLUSIONS:
These results demonstrate that consumption of an ad libitum, high-carbohydrate diet alone or in combination with aerobic exercise training results in weight loss and improved insulin sensitivity. Furthermore, exercise combined with this diet appears to limit additional increases in insulin sensitivity due to muscle glycogen supercompensation with a concomitant adaptive response of glycogen synthase.
Meat Intake and Insulin Resistance in Women without Type 2 Diabetes
In conclusion, it appears that meat intake, particularly red and processed meats, is associated with higher levels of insulin resistance in middle-aged women without type 2 diabetes. Among the many potential confounders examined in this study, BMI and body fat percentage influenced the association significantly. Consequently, both a lower meat intake and lower levels of body fat appear important in reducing the likelihood of insulin resistance, especially in this sample. Consumption of very lean meats (VLM) does not seem to play a role in insulin resistance. To decrease the likelihood of insulin resistance, prudence in the amount and type of meat consumed may be helpful.