1.
The effect of periodic ketogenic diet on newly diagnosed overweight or obese patients with type 2 diabetes.
Li, S, Lin, G, Chen, J, Chen, Z, Xu, F, Zhu, F, Zhang, J, Yuan, S
BMC endocrine disorders. 2022;22(1):34
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Currently, the ketogenic diet is gaining popularity in managing Type 2 diabetes (T2D). Ketogenic diets replace carbohydrates with fat and include limited carbohydrates and adequate protein. This randomised controlled trial evaluated the effects of the 12-week ketogenic diet on sixty overweight or obese T2D patients. Both the ketogenic and control diabetes diet groups achieved significant reductions in weight, body mass index, waist circumference, triglycerides, total cholesterol, low-density lipoprotein, high-density lipoprotein, fasting blood glucose, fasting insulin, and HbA1c. However, the ketogenic group showed significantly greater reductions in body mass, blood lipids, and blood glucose than the control group. In the ketogenic diet group, serum uric acid levels were higher than those in the control diet group. It was found that the control diet group adhered to the diet for a longer period than the ketogenic diet group, whose willingness to adhere to the diet long-term was weaker. More robust long-term studies are needed to evaluate the long-term effects of a ketogenic diet. In this study, more patients who followed the ketogenic diet experienced hypoglycaemic events during the first four weeks. Healthcare providers should exercise caution when recommending a short term therapeutic ketogenic diet.
Abstract
BACKGROUND The ketogenic diet (KD) is characterized by fat as a substitute of carbohydrates for the primary energy source. There is a large number of overweight or obese people with type 2 diabetes mellitus (T2DM), while this study aims to observe periodic ketogenic diet for effect on overweight or obese patients newly diagnosed as T2DM. METHODS A total of 60 overweight or obese patients newly diagnosed as T2DM were randomized into two groups: KD group, which was given ketogenic diet, and control group, which was given routine diet for diabetes, 30 cases in each group. Both dietary patterns lasted 12 weeks, and during the period, the blood glucose, blood lipid, body weight, insulin, and uric acid before and after intervention, as well as the significance for relevant changes, were observed. RESULTS For both groups, the weight, BMI(body mass index), Waist, TG (triglyceride), TC(cholesterol), LDL (low-density lipoprotein cholesterol), HDL (high-density lipoprotein cholesterol), FBG (fasting glucose), FINS (fasting insulin), HbA1c (glycosylated hemoglobin) were decreased after intervention (P < 0.05), while the decrease rates in the KD group was more significant than the control group. However, UA(serum uric acid) in the KD group showed an upward trend, while in the control group was not changed significantly (P > 0.05).The willingness to adhere to the ketogenic diet over the long term was weaker than to the routine diet for diabetes. CONCLUSION Among the overweight or obese patients newly diagnosed as type 2 diabetes mellitus, periodic ketogenic diet can not only control the body weight, but also control blood glucose and lipid, but long-term persistence is difficult.
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The effects of a ketogenic diet on exercise metabolism and physical performance in off-road cyclists.
Zajac, A, Poprzecki, S, Maszczyk, A, Czuba, M, Michalczyk, M, Zydek, G
Nutrients. 2014;6(7):2493-508
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While it is well-known that nutrient availability affects numerous aspects of exercise metabolism, new concepts of improving endurance performance are being explored. Sports nutrition has historically focused on a high carbohydrate diet to increase glycogen stores, however there is increasing evidence that a low carbohydrate, high fat diet may benefit endurance athletes. The aim of this crossover study was to determine the effects of a long-term keteogenic diet on aerobic performance and exercise metabolism in eight male cyclists. The participants were assigned to either a mixed or ketogenic diet for one month with a one-week recovery period and performed an exercise protocol consisting of moderate and high intensities. The findings indicated that consuming a low carbohydrate diet promotes fat oxidation during moderate-intensity and reduces post-exercise muscle damage. Based on these results, the authors conclude that long-term, high fat diets may be favourable for aerobic endurance athletes during the preparatory season.
Abstract
The main objective of this research was to determine the effects of a long-term ketogenic diet, rich in polyunsaturated fatty acids, on aerobic performance and exercise metabolism in off-road cyclists. Additionally, the effects of this diet on body mass and body composition were evaluated, as well as those that occurred in the lipid and lipoprotein profiles due to the dietary intervention. The research material included eight male subjects, aged 28.3 ± 3.9 years, with at least five years of training experience that competed in off-road cycling. Each cyclist performed a continuous exercise protocol on a cycloergometer with varied intensity, after a mixed and ketogenic diet in a crossover design. The ketogenic diet stimulated favorable changes in body mass and body composition, as well as in the lipid and lipoprotein profiles. Important findings of the present study include a significant increase in the relative values of maximal oxygen uptake (VO2max) and oxygen uptake at lactate threshold (VO2 LT) after the ketogenic diet, which can be explained by reductions in body mass and fat mass and/or the greater oxygen uptake necessary to obtain the same energy yield as on a mixed diet, due to increased fat oxidation or by enhanced sympathetic activation. The max work load and the work load at lactate threshold were significantly higher after the mixed diet. The values of the respiratory exchange ratio (RER) were significantly lower at rest and during particular stages of the exercise protocol following the ketogenic diet. The heart rate (HR) and oxygen uptake were significantly higher at rest and during the first three stages of exercise after the ketogenic diet, while the reverse was true during the last stage of the exercise protocol conducted with maximal intensity. Creatine kinase (CK) and lactate dehydrogenase (LDH) activity were significantly lower at rest and during particular stages of the 105-min exercise protocol following the low carbohydrate ketogenic diet. The alterations in insulin and cortisol concentrations due to the dietary intervention confirm the concept that the glucostatic mechanism controls the hormonal and metabolic responses to exercise.
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Comparison of short- versus long-term ketogenic diet for intractable infantile spasms.
Kang, HC, Lee, YJ, Lee, JS, Lee, EJ, Eom, S, You, SJ, Kim, HD
Epilepsia. 2011;52(4):781-7
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Ketogenic diets (KD) have shown favourable effects on childhood epilepsy. However, these is reluctance to use these as a form of treatment because of the possible adverse impact on the growing child. This study compared short (8 months) and long term (24 months) KD on infantile spasms. 40 children aged between 6 and 60 months who had achieved seizure free outcomes within 6 months of a KD were randomly assigned to to short (16 patients) and long term (19 patients) trial groups. The children completed a KD with a 3:1 ratio of fat to non-fat and also took multivitamins, calcium, vitamin D2 and L-carnitine. The study measured seizure relapse and frequency after the KD. Adverse effects most commonly experienced by the children during the KD included gastrointestinal disturbances (nausea, vomiting, diarrhoea, constipation), and elevated lipids. Growth failure only occurred in the group who maintained the KD long term (7 out of 19). The authors concluded that a KD for 8 months in children with infantile spasms appears justified; it has the benefit of less growth disturbances but similar spasm-free outcomes compared to longer term durations.
Abstract
PURPOSE To compare the prognoses between short-term (8 months) and conventional long-term (> 2 years) trials involving patients with refractory infantile spasms who successfully completed the ketogenic diet (KD). METHODS Of 40 patients who achieved seizure-free outcomes and showed improvement in hypsarrhythmic patterns within 6 months of the KD, with a 3:1 fat to nonfat ratio as an add-on treatment, 16 patients were randomized into the short-term trial group and the diet was tapered throughout two additional months. Twenty-four patients were randomized into a long-term trial group, and 19 patients could successfully discontinue the diet after 2 years. Primary outcome measures included seizure relapse and frequency of 35 patients for > 12 months after successful completion of the KD. KEY FINDINGS Of 16 patients in the short-term trial group, two patients relapsed with clusters of spasms, and one patient had recurrence of occasional focal seizures. Of 19 patients in the long-term trial group, two patients progressed to Lennox-Gastaut syndrome and one patient experienced recurrence of occasional focal seizures with secondary generalization. An early response to the KD, evidenced by short latency before seizure freedom and disappearance of hypsarrythmia and cryptogenic etiology, may indicate a successful early discontinuation of the KD. Significant growth failure was complicated only in conventional long-term trial group. SIGNIFICANCE Use of the KD for only 8 months in children who become spasm-free appears to be justified, with similar outcomes, recurrence rate, and less growth disturbance than a longer-term, traditional use.