High-Protein or Low Glycemic Index Diet-Which Energy-Restricted Diet Is Better to Start a Weight Loss Program?

BACKGROUND: To date, no crossover studies have compared the effects of high-protein (HP) and low glycemic index (LGI) diets applied as starting energy-restricted diets. METHODS: Thirty-five overweight or obese volunteers with sedentary lifestyles aged 41.4 ± 11.0 years, with body mass index (BMI) of 33.6 ± 4.2 kg/m2, without diabetes, completed an 8-week randomized crossover study of an energy-restricted diet (reduction of 30%; approximately 600 kcal/day). The anthropometric parameters, body composition, 24 h blood pressure, and basic metabolic profile were measured at baseline and after completing the two 4-week diets; i.e., the HP (protein at 30% of the daily energy intake) or LGI diet, followed by the opposite diet. All subjects maintained food diaries and attended six counselling sessions with a clinical dietitian. RESULTS: The final weight loss was not significantly different when the HP diet was used first but was associated with a greater loss of fat mass: 4.6 kg (5.8; 3.0 kg) vs. 2.2 (4.5; 0.8); p < 0.025, preserved muscle mass, and reduced LDL-cholesterol. CONCLUSIONS: A short-term HP diet applied as a jump-start diet appeared to be more beneficial than an LGI diet, as indicated by the greater fat mass loss, preservation of muscle mass, and better effects on the lipid profile.

Nutritional Strategies for the Individualized Treatment of Non-Alcoholic Fatty Liver Disease (NAFLD) Based on the Nutrient-Induced Insulin Output Ratio (NIOR).

Nutrients play a fundamental role as regulators of the activity of enzymes involved in liver metabolism. In the general population, the action of nutrients may be affected by gene polymorphisms. Therefore, individualization of a diet for individuals with fatty liver seems to be a fundamental step in nutritional strategies. In this study, we tested the nutrient-induced insulin output ratio (NIOR), which is used to identify the correlation between the variants of genes and insulin resistance. We enrolled 171 patients, Caucasian men (n = 104) and women (n = 67), diagnosed with non-alcoholic fatty liver disease (NAFLD). From the pool of genes sensitive to nutrient content, we selected genes characterized by a strong response to the NIOR. The polymorphisms included Adrenergic receptor (b3AR), Tumor necrosis factor (TNFα), Apolipoprotein C (Apo C III). Uncoupling Protein type I (UCP-1), Peroxisome proliferator activated receptor γ2 (PPAR-2) and Apolipoprotein E (APOEs). We performed three dietary interventions: a diet consistent with the results of genotyping (NIOR (+)); typical dietary recommendations for NAFLD (Cust (+)), and a diet opposite to the genotyping results (NIOR (-) and Cust (-)). We administered the diet for six months. The most beneficial changes were observed among fat-sensitive patients who were treated with the NIOR (+) diet. These changes included improvements in body mass and insulin sensitivity and normalization of blood lipids. In people sensitive to fat, the NIOR seems to be a useful tool for determining specific strategies for the treatment of NAFLD.

Level of knowledge concerning diet in type 2 diabetic patients and nurses.

Introduction: Among patients with diabetes, there are many myths concerning food products which are believed to lower or not influence the blood glucose (BG) level. The aim of this study was to assess the knowledge of patients with diabetes and hospital nurses concerning popular food products and their impact on BG levels. Materials and methods: The study group consisted of 250 patients with diabetes (DM), members of the Polish Diabetes Association; the other group consisted of 123 healthy nurses (N) from 3 hospitals in Szczecin, Poland. Participants were asked to complete a questionnaire on products common in diabetic diet (grapefruit, honey, coffee substitute, diabetic chocolate, milk soup, pork neck) and their influence on BG levels. Results: The highest percentage of wrong answers was given for pork (DM 71%; N 83%, NS) and grapefruit (DM 51%; N 77%, p < 0.01), while the most correct answers were for honey (DM 69%; N 80%; p < 0.05) and milk soup (DM 64%; N 67%, NS). Negative correlation was found between the number of correct answers and the age of patients (r(s) = −0,14; p < 0.01;) and no correlation between the number of correct answers and the duration of diabetes mellitus (NS). Patients treated with insulin provided correct answers significantly more frequently than patients on oral medication only (44% vs 34.8%; p < 0.01). Conclusions: 1. The level of knowledge concerning products commonly used in diabetic diet among patients with diabetes and hospital nurses is low. 2. Both groups, patients and hospital nurses, need education about diabetic diet.

Melatonin-induced modulation of glucose metabolism in primary cultures of rabbit kidney-cortex tubules.

The effect of melatonin on glucose metabolism in the presence and absence of insulin has been investigated in the primary cultures of renal tubules grown in a defined medium. In the absence of glucose in the medium containing 5 microg/mL of insulin and 2 mm alanine + 5 mm glycerol + 0.5 mm octanoate, 100 nm melatonin stimulated both glucose and lactate synthesis, while in the medium devoid of insulin melatonin action was negligible. Melatonin-induced increase in glucose and lactate synthesis was accompanied by an enhancement of alanine and glycerol consumption. In view of measurements of [U-14C]L-alanine and [U-14C]L-glycerol incorporation into glucose, it is likely that melatonin increased alanine utilization for glucose production, while accelerated lactate synthesis was because of an enhanced glycerol consumption. As (i) 10 nm luzindole attenuated the stimulatory action of melatonin on glucose formation and (ii) the indole induced a decrease in intracellular cAMP level, it seems likely that in renal tubules melatonin binds to ML1 membrane receptor subtype. In view of a decline of intracellular fructose-1,6-bisphosphate content accompanied by a significant rise in hexose-6-phosphate and glucose levels, melatonin might result in an acceleration of flux through fructose-1,6-bisphosphatase probably because of an increase in the active, dephosphorylated form of this enzyme. Thus, the administration of melatonin in combination with insulin might be beneficial for diabetic therapy because of protection against hypoglycemia.