ARTICLE #3 SUMMARY

ARTICLE #3 SUMMARY

Sofer, S., Eliraz, A., Kaplan, S., Voet, H., Fink, G., Kima, T., & Madar, Z. (2011). Greater weight loss and hormonal changes after 6 months diet with carbohydrates eaten mostly at dinner. Obesity (Silver Spring, Md.), 19(10), 2006-14

·         Study investigated the effect of a low-calorie diet with carbs eaten mostly at dinner on anthropometric (weight and measurement of the body) , hunger/satiety, biochemical and inflammatory parameters. They also measured hormonal secretions.

·       This was randomized clinical trial with random blind group assignment and inclusion of a control group. However, the participants were not chosen at random but included only healthy obese male and female police officers (BMI over 30 but do not have hypertension, diabetes, etc). The analysis used was appropriate (T-test, Anova, and they controlled for bias with analysis of covariance, etc). Hormone levels were taken and hunger questionnaires were completed every 4 hours before meals on days 7, 90 and 180 of the diets)

·         The study built upon previous research that showed the patterns of the following bodily secretions:

ü  Leptin is the “satiety hormone” that regulates hunger, satiety and food intake. Our bodies increase its secretion between 1600hrs (4pm) and 0100 (1am) – meaning its levels are highest by dinner time and highest while we are usually asleep.

ü  Adiponectin is a protein that regulates energy and lipid / carb metabolism (which reduces serum glucose/lipids – improving insulin sensitivity and having an anti inflammatory effect). This protein in obese individuals is found to be low throughout the day.

·         Researchers are testing to see if an innovative dietary regimen could work with the obese persons body and be beneficial in aiding obesity. Similar studies examining the Muslim Ramadan diet were discussed (when they fast all day and eat a carbohydrate rich evening meal). They hypothesized that holding out carbs until dinner will alter the secretion of these hormones into a new schedule that is higher during the day when the majority of calories are consumed (making people feel less hungry and more satisfied).

·         THE DIET: Standard low calorie diet – 20% protein, 30-35% fat, 45-50% carbohydrates = 1,300 – 1,500 calories daily. (I cannot post the example of their daily food intake from the study because of copyright law)

·         The control group and experimental group ate the EXACT same foods, the only difference being the time of day in which carbs were eaten. Control group contained their carbs throughout the day with every meal and the experimental ate theirs at dinner.

·          BODY MEASUREMENT RESULTS:

ü  Significantly greater weight loss was found in the experimental group (11.6 vs 9.06kg) – (P=0.024)

ü  Trends of greater BMI reduction were found (3.99 vs. 3.16 BMI points), abdominal circumference reduction (11.7 vs. 9.39 cm) and absolute body fat percent (6.98 vs. 5.13%) were found in the experimental group. After controlling for baseline measurements, these results were not scientifically significant (P=>0.05) but still noteworthy.

·         HUNGER/SATIETY QUESTIONNAIRE RESULTS

ü  HUNGER: Control group felt significantly hungrier at noon on day 90 and 180 compared to first week on diet (5.9%); experimental group felt less hungry compared to the first week (27.7%) on diet. The most significant difference (P=0.03) between the groups with hunger was found in the evening of day 180 (28% increase in hunger vs. 6.6% decrease in hunger).

ü  URGE TO EAT: Experimental diet participants had a 67% reduction in the urge to eat vs. 19% of the control diet group when comparing to the first week of the diet.

ü  PREOCCUPATION WITH THOUGHTS OF FOOD: Experimental group had no increase preoccupation with thoughts of food vs. 33% of the control group having increased preoccupation with thoughts of food on day 180 compared to the first week on diet.

·         BIOCHEMICAL RESULTS

ü  Day 180 on the experimental diet showed significantly lower average daily insulin concentrations when compared to baseline and control group (68%, P=<0.05)

ü  Experimental diet led to significant decrease (20%, P=0.01) in fasting glucose vs. 8.3% decrease in the control group

ü  HOMA (method used to quantify insulin resistance and beta-cell function) 30.9% decrease found in experimental group vs. 19.7% increase in the control group. These results were significant at P=0.015.

ü  Both diets led to significant reduction in morning fasting triglyceride concentrations compared to baseline when measured on days 90 and 180 (P=0.0001).

ü  Experimental diet led to 8.1% significant decrease in total cholesterol concentrations (P=0.01)

ü  HDL-cholesterol (good cholesterol) increase in experimental diet  was significantly greater compared to the control diet increase after 180 days (P=0.022)

·         SERUM INFLAMMATORY LEVELS

ü  Experimental diet had greater CRP reduction (protein found in the blood that rises in response to inflammation) although not scientifically significant once adjusting for baseline levels

ü  Experimental diet had significantly lower TNF-a concentrations (small cell-signaling protein molecules that stimulate an increase or decrease in plasma concentrations in response to inflammation). Experimental diet led to a 9.2% decrease in TNFa levels va. The control group had a 16.1% increase compared to baseline.

·         SERUM HORMONAL LEVELS

ü  Both diets led to an average 12-hours leptin concentrations on day 90 and 180 (P=<0.05)

üExperimental diet led to significant increase (43.5%, P=<0.05) in average 12-h adiponectin (regulates glucose levels and fatty acid breakdown) concentrations vs. the control diets insignificant 13.9% after 180 days.