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.
