• Journal of Korean Medicine for Obesity Research
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• v.5 no.1
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• pp.121-131
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• 2005

During last few decades dietary guidelines for the weight management mainly have focused on a low-fat, high carbohydrate diet. Carbohydrate was supposed to be low-dense, highly satiating as well as it affects little on the lipogenesis. Although low-fat diet has significant weight-reducing effect, the loss was modest and usually regained after cessation of the diet. Furthermore, low-fat, modest-carbohydrate diet did not impact on the ever increasing rates of overweight and obesity. Alternative approaches include low-carbohydrate diet, high-carbohydrate diet and low-glycemic index diet. Although none of above mentioned diet have sufficient evidence for standard weight management diet, short-term efficacy and safety are being approved continuously. Low-carbohydrate diet contains less than 45% of carbohydrate in daily energy consumption, it is claimed to have more satiating effect and to improve metabolism. However, low compliance due to the limitation of food choice should be considered on prescribing the diet. High-carbohydrate which contains 90% of carbohydrate in total daily energy consumption, is effective in providing satiety and lowering total calorie intake and cholesterol. On the other hand, nutritional unbalance should be took into account. Low-glycemic index diet is based on the theory that contemporary diet contains significantly less fiber and unrefined carbohydrate, therefore insulin secretion is disturbed. Because low glycemic index food slowly increase blood glucose and insulin level, it induces much satiating effect and may decrease calorie ultimate intake. However, poor standardization of glycemic index is one of the main obstacle for the diet to be applied in the clinic. Meanwhile, high fructose food and beverage should be discouraged because it has little satiating effect and may cause insulin resistance. High fiber food is another recommendation for healthy, lean diet.

• Journal of Nutrition and Health
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• v.29 no.7
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• pp.689-702
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• 1996

The purpose of this experiment was to compare the effects of tryptophan administration on nutritional status of female rats which consumed reserpine and 6% casein diet with different carbohydrate contents(87%, 65%, 44% respective). Final body weight, body weight gain, FER, plasma amino acid concentration and microsomal cytochrome P 450 content in liver were measured and microscopic structure of hepatocytes was observed. In low-protein diet, the higher the carbohydrate content of diet was, the lower the damage was in the rat's liver. Tryptophan administration after dose of reserpine induced more effective recovery from liver damage of rats in high carbohydrate diet group than that in low carbohydrate diet group. In conclusion, the general nutritional assessments such as final body weight and body weight gain provided better estimate of the degree of structural changes in hepatocytes than functional assessment such as plasma amino acid concentration or liver microsomal cytochrome P450.

• Journal of Nutrition and Health
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• v.20 no.2
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• pp.135-144
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• 1987

This study was carried out to investigate the effect of dietray carbohydrate level on the lipid and Ca metabolism, and on immune response in the process of aging. Sprag\ulcornerue - Dawley male rats of 12 months of age were fed either high carbohydrate or low carbohydrate diet for 9 months. With increasing age from 12 months to 21 months, there was no significant increase in body weight, however, the epididymal fat pat weight and total serum lipid tend to become higher, and the inorganic/organic matterratio in bone tends to become lower. This suggests that body fat accumulation increase and bone mass decrease with age. Rats fed low carbohydrate diet showed the higher epididymal fat pat weight, and the lower Ca content in femur and scapular compared to high carbohydrate diet fed rats. The immune response was also lower in low carbohydrate diet group judged by the lower thymus and spleen index and by the lower response to PHA and ConA stimulation. The results of this study suggests that the dietary level of carbohydrate and fat may play an important role in the process of aging. It could be recommended to practice high carbohydrate -low fat diet for the elderly to reduce the risk of degenerative diseases.

• Nutritional Sciences
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• v.7 no.2
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• pp.65-69
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• 2004

A study was carried out to determine the effect of a very low-carbohydrate diet on weight gain, body composition, and serum levels of cholesterol, triacylglycerol, glucose, ketone bodies and insulin. Twenty rats (mean initial weight, 212 g) were divided into two groups and each group was assigned a conventional high-carbohydrate diet (control) or a very low-carbohydrate diet containing 59.8% ground pork rind snack and fed the diet for four weeks. Average daily body weight gain was not different between the two groups during the first two weeks, but was significantly lower in rats fed the very low-carbohydrate diet than in those in the control group during third (p<0.05) and fourth weeks (p<0.01). Feedintake as well as energy intake was lower in rats fed the very low-carbohydrate diet than in those in the control group. The very low-carbohydrate diet reduced (p<0.01) serum triacylglycerol (34$\pm$83 vs 82$\pm$8 mg/l00 mL) and insulin (3.90$\pm$0.53 vs 7.60$\pm$0.61 $\mu$IU/mL) levels, while increasing (p<0.01) ketone body level (368$\pm$25 vs 236$\pm$24 $\mu$mol/L), compared with the control. Serum glucose and total cholesterol levels were not different (p>0.05) between the two dietary treatments. Proximate analysis of carcasses showed that the very low-carbohydrate diet decreased (p<0.01) body fat (26.1$\pm$1.04 vs 30.5$\pm$0.86%), while increasing (p<0.01) body protein (63.1$\pm$0.94 vs 59.4$\pm$0.70%) contents. Results indicate that short-term feeding of a very low-carbohydrate diet is beneficial for alleviating risk factors known to involve cardiovascular diseases or artherosclerosis. However, more studies with model animals as well as humans are recommended to examine the long-term health benefits of low-carbohydrate diets.

• Journal of Nutrition and Health
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• v.33 no.8
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• pp.873-881
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• 2000

Recent research reported health risks associate with high carbohydrates diets. Objectives of this study were to evaluate in a cross-sectional study if high carbohydrate diet is associated with coronary heart disease(CHD) risk factors: examined blood concnetration of triglyceride(TG), total cholesterol, high density lipoprotein cholesterol(HDL-C), plasma glucose, systolic blood pressure(BP), body mas index(BMI), wasit-hip ratio(WHR) and waist-stature ratio(WSR). Using the most recent US National Health and Nutrition Examination Survey(IIINHANES III) data, the nationally representative US population (3772 men, 4095 women of 25-64 years of age) was divided into low vs. high carbohydrate diet groups(below 40% vs. above 60% energy intake from cab carbohydrates) and compared by the CHD risk factors. Triglyceride was higher(p<0.001) in the high carbohydrate group, whereas high density-lipoprotein cholesterol(HDL-C)was lower(p<0.01) in the high carbohydrate diet group. In plasma glucose, there was no significant differences between high carbohydrate diet and low carbohydrate diet. In adiposity(BMI, WHR and WSR), it also showed no significant differences, After adjustment for age, ethnicity, alcohol and smoking in upper 60%-carbohydrate diet, Odds Ratio of TG and HDL-C were 1.42 and 1.23 in men and 1.22 and 1.17 in women. 50-60% carbohydrate diet was associated with decreased risk of CHD. Dietary guidelines for Koreans recommend 60-70% of total energy from carbohydrate, as Koreans traditionally consumed high carbohydrate diets. In a cross-sectional population of adults, diets containing 55-60% energy from carbohydrate were suggested as a dietary guideline of carbohydrate intake for Koreans. (Korean J Nutrition 33(8) : 873-881, 2000)

• Journal of Nutrition and Health
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• v.22 no.4
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• pp.266-274
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• 1989

The current study was undertaken to determine the effects of the ratios of dietary fat to carbohydrate and energy restriction on insulin sensitivity in the growing rats. Male rats weighting 80-90g were fed experimental diets for two weeks. Rats were killed and epiddymal adipose tissue were removed and sliced. Explants of adipose tissues were incubated for 2 hours in KRB(Krebs-Ringer bicarbonate) buffer containing various concentrations of human insulin and [U-14C]glucose. Insulin sensitivity was determined as glucose conversion to total lipids (lipogenesis) during 2 hr incubation. Exp't I : Effects of Ratios of Fat to Carbohydrate on Insulin Sensitivity. Eighteen male rats were fed 3 diets for 2 weeks. Diet 1 was low fat-high carbohydrate (4% soybean oil and 66.5% cornstarch) ; diet 2, medium fat-medium sarbohydrate(12% soybean oil and 58.5% cornstarch) ; diet 3, high fat-low carbohydrate (20% soybean oil and 50.5% cornstarch). Insulin sensitivity was higher in the order of LF-HC, MF-HC and HF-LC diet groups (p<0.05), i.e, lipogenesis was higher at all insuline concentration in the explants from rats fed LF-HC diet. However, thers was no significant difference in body weight gain and epididymal adipose tissue weight among treatments. Exp't II ; Effects of Energy Restriction on Insulin Sensitivity. Twelve rats were grouped into ad libitum feeding and restricted feeding(70% of ad libitum). The experimental diet was medium fat-medium carbohydrat diet as used in the Exp't I. Restricted feeding group tended to show higher insulin sensitivity compared to ad libitum group. However, there was no statistical difference between two groups. As expected, body weight gain and epididymal adipose tissue were higher in the ad libitum group. In summary, the resutls of the current study showed that the epididymal adipose tissue taken from the rats fed low fat-high carbohydrate diet showed higher insulin sensitivity compared to those fed high fat-low carbohydrate, and that resticted feeding tended to elevate insulin sensitivity in these tissues.

• Archives of Obesity and Metabolism
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• v.3 no.1
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• pp.9-13
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• 2024

The prevalence of obesity has been increasing worldwide. Several dietary treatments have been suggested to control weight, and recent guidelines recommend individualizing the composition of macronutrients. Carbohydrates are the most important nutrients in meals, and carbohydrate restriction is a dietary strategy that promotes weight loss. A low-carbohydrate diet is effective for short-term weight loss and can help improve glycated hemoglobin, systolic blood pressure, diastolic blood pressure, and triglyceride levels; however, the long-term effects and safety of this diet remains doubtful. In the short term, there is a risk of gastrointestinal symptoms such as vomiting, diarrhea, constipation, and gastroesophageal reflux, and type 1 diabetes patients are at risk of severe hypoglycemia, while in the long term, it can lead to malnutrition and decreased exercise capacity. Thus, rather than limiting the intake of carbohydrates, it is important to limit the intake of refined grains, sugar, honey, syrup, and sweetened beverages while maintaining the planned carbohydrate intake rate and improving meal quality.

• Korean Journal of Community Nutrition
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• v.24 no.6
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• pp.485-496
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• 2019

Objectives: This study was conducted to investigate the effect of a 6-week low-calorie diet (LCD) program including high protein-low carbohydrate protein bar on weight loss, blood pressure, and blood lipid profile in 40 overweight women according to dietary compliance. Methods: Subjects were 62 healthy overweight women (BMI ≥ 23.0 or body fat percentage ≥ 28%), aged 20~59 yrs who were provided a high protein-low carbohydrate protein bar (each 35 g, 154 kcal, protein energy %: 28.6%, carbohydrate energy %: 38.7%) as part of dinner for 6 weeks. Forty subjects who completed the whole diet program were categorized into high compliance (HC) group (days of eating protein bar ≥ 5 weeks) or low compliance (LC) group (days < 5 weeks). Results: Energy intake significantly decreased from 1,867.5 kcal at baseline to 1,137.4 kcal at 6 weeks for the HC group and from 1,971.7 kcal to 1,362.2 kcal for the LC group, respectively. On the other hand, a significant increase in protein energy percentage was observed in each group (HC group: 3.5%, LC group: 2.2%). Both groups showed significant decreases in weight (HC group: 1.8 kg, LC group: 1.1 kg), BMI, fat mass, systolic blood pressure, total cholesterol, and LDL-cholesterol. Reduction of body fat percentage and diastolic blood pressure were only observed in the HC group. Conclusions: The inclusion of a high protein-low carbohydrate protein bar as part of a low-calorie diet for a short period can be effective to achieve weight loss and concomitantly improve blood cholesterol level without serious physiological side effects. More evident results can be achieved by eating a diet with low calorie diet including high protein-low carbohydrate protein bar for more than 5 weeks.

• Preventive Nutrition and Food Science
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• v.21 no.1
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• pp.57-61
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• 2016

Dietary proteins influence colorectal cancer (CRC) risk, depending on their quantity and quality. Here, using pyrosequencing, we compared the fecal microbiota composition in Balb/c mice fed either a normal protein/carbohydrate diet (ND, 20% casein and 68% carbohydrate) or a high-protein/low-carbohydrate diet (HPLCD, 30% casein and 57% carbohydrate). The results showed that HPLCD feeding for 2 weeks reduced the diversity and altered the composition of the microbiota compared with the ND mice, which included a decrease in the proportion of the family Lachnospiraceae and Ruminococcaceae and increases in the proportions of the genus Bacteroides and Parabacteroides, especially the species EF09600_s and EF604598_s. Similar changes were reported in patients with inflammatory bowel disease, and in mouse models of CRC and colitis, respectively. This suggests that HPLCD may lead to a deleterious luminal environment and may have adverse effects on the intestinal health of individuals consuming such a diet.

• Journal of Nutrition and Health
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• v.6 no.4
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• pp.15-22
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• 1973

Sodium chloride plays an important role as the main condiment at daily meal. It is well known that humans require sodium chloride as an essential nutrient to keep the homeostasis of electrolytes. The amounts of salt intake may be a reflection of geography, culture and food habit rather than necessity. Lee has reported (1962) that Koreans ingest high amounts of sodium chloride in their meals, with an intake of excess carbohydrate (80-90% of total Calories) and low protein in their diet. This includes large amounts of rice, Kimchi and other fermented soybean products common in the Korean diet. This investigation was designed to study the dietary relations of sodium chloride to other nutrients in the Korean diet. Twenty four albino male rats, weighing from 290-300g, were divided into four dietary groups according to the amounts of carbohydrate, protein and fat in the basal diet. Each diet contained a rice powder as a carbohydrate source. Diet I was a control diet, Diet II, low protein, Diet III, low protein and low fat diet and Diet IV, low fat diet. All rats were provided with 3% sodium chloride solution. Diet and salt solution were given ad libitum. The experiment was carried out for 9 weeks during which time the body weight, the food intake, and 3% sodium chloride solution consumption were determined. At the 9th week, the urine was collected the blood sample from the artery of each rat for the analysis of sodium and potassium and other chemical studies. The rats were sacrificed and the kidney, adrenal, liver and spleen were measured, and observed changes of the pathological tissue in the kidney and adrenal. The results were summarized as follows: 1) The growth rate was higher in Diet I than in the other experimental diets (II, III and IV) after 4 weeks. There was no significant difference found between the experimental Diets II, III and IV. 2) The daily food intake was greater in the experimental diets II, III and IV than in the control diet. However, there was no difference among the high carbohydrate diets Diet II, III and IV. 3) The daily water (3% sodium chloride solution) intake was also greater in the Diets II, III and IV, than in the control diet. However, there was no difference between Diets II, III and IV. 4) The concentration of sodium and potassium in the blood were within the normal range in all diets. 5) The amount of sodium chloride in the urine was significantly greater in Diets II, III and IV than in the control diet. Diets II, III, IV had a larger amount of sodium solution consumption. 6) Observation of pathological tissue in the experimental diets found a cell proliferation in the glomerlulus of the kidney, while such change was not found in the control diet.