Participants
and Diets
25 adults aged 50-69, with
type 2 diabetes, were randomised to follow a Paleo diet or the American
Diabetes Association diet. Three meals
and three snacks were provided. An
attempt to avoid weight loss was made by calculating maintenance energy needs and
then adjusting calorie intake if 3lb (~1.35kg) of weight loss occurred.
“The Paleo diet consisted of meat, fish, poultry, eggs, fruit,
vegetables, tree nuts, canola oil, mayonnaise and honey. We excluded dairy
products, legumes, cereals, grains, potatoes and products containing potassium
chloride. Some foods, such as mayonnaise, carrot juice and domestic meat, were
not consumed by hunter gatherers but contain the general nutritional
characteristics of pre-agricultural foods.”
In addition, there were 3 ramp
up diets for 7 days for those in the Paleo group to “allow for adaptation of the subjects’ intestinal tract and potassium
handling systems to adjust to the markedly higher dietary content of the fiber
and potassium in the Paleo diet”
The ADA diet is not defined in
the paper except for “…containing
moderate salt intake, low-fat dairy, whole grains and legumes”, as opposed
to the exclusion of these foods in the Paleo diet (excluding added salt, not
all salt). There is also no measurement
of what the participants ate, except for macronutrients and some
micronutrients. Calorie intake was
identical and macronutrient ratios were fairly similar although the Paleo group
had slightly lower protein, fat and SFA; and slightly higher carbohydrate and
MUFA.
|
ADA
|
Paleo
|
Energy (kcal)
|
3000.5
|
3001.5
|
Pro:Fat:Carb (%)
|
20.3:28.8:54.4
|
18.5:27.0:58.2
|
SFA:MUFA:PUFA
(%)
|
6.4:13.8:6.1
|
3.6:14.8:6.3
|
Sodium (mg)*
|
4112
|
1580
|
Potassium (mg)*
|
6337
|
12246
|
Calcium (mg)
|
1998
|
932
|
Fibre (g)**
|
15g
|
42g
|
* The figures for sodium and
potassium intake in the Paleo group are in mmol (the unit they reported), while
those for the ADA group seem to be in mg
** The fibre intake in the
Paleo group is what you would expect with 3000 calories, a high carbohydrate
diet and most of the carbohydrates coming from fruit and vegetables. The fibre intake in the ADA group is very low
and if it’s correct, then the ADA group were probably eating a lot of refined
grains rather than whole grains
Results
Glucose control: fasting glucose significantly decreased in the
Paleo group, with no change in the ADA group, although the difference between
the groups was only P=0.3. Consequently,
fructosamine, a short term marker of glycemic control, significantly decreased
in the Paleo group, with no change in the ADA group and a near significant
difference between the groups (P=0.06).
HbA1c significantly decreased in both groups, despite no improvement in
fasting glucose and fructosamine in the ADA group. Both groups had minor improvements in insulin
sensitivity (P = 0.1 and 0.09 respectively), although among the most insulin
resistant participants, those in the Paleo group, but not the ADA group, had a
significant improvement in insulin sensitivity (see figure below)
Blood lipids: both groups had decreases in HDL-C, probably due to
lower fat intake. The Paleo group, but
not the ADA group, had significant decreases in total-C and LDL-C probably due
to both the very low SFA intake and high fibre intake. Triglycerides almost significantly decreased
in the Paleo group, but not the ADA group, despite higher carbohydrate intake
and no difference in weight loss and baseline triglycerides, which may be due
to high fibre intake.
|
ADA Diet
|
Paleo Diet
|
P Value Between
Groups
|
||
Difference
|
P Value
|
Difference
|
P Value
|
||
Weight (kg)
|
-2.1±1.9
|
0.004
|
-2.4±0.7
|
<0.001
|
0.7
|
Systolic blood pressure
|
-2±13
|
0.7
|
-4±12
|
0.2
|
0.6
|
Diastolic blood pressure
|
0±12
|
0.9
|
-1±6
|
0.4
|
0.6
|
Mean arterial pressure
|
-1±7
|
0.8
|
-2±7
|
0.3
|
0.6
|
HbA1c
|
-0.18±0.24
|
0.04
|
-0.30±0.49
|
0.04
|
0.5
|
Fasting glucose (mmol/l)
|
+0.6±1.8
|
0.4
|
-1.3±1.4
|
0.008
|
0.3
|
Fructosamine (mg/dl)
|
-3±28
|
0.7
|
-34±41
|
0.009
|
0.06
|
Insulin sensitivity
|
+1.0±1.9
|
0.1
|
+1.3±2.6
|
0.09
|
0.8
|
Total-C (mg/dl)
|
-9±25
|
0.2
|
-26±27
|
0.003
|
0.2
|
Trigs (mg/dl)
|
-5±63
|
0.8
|
-23±46
|
0.08
|
0.5
|
HDL-C (mg/dl)
|
-6±8
|
0.03
|
-8±7
|
0.001
|
0.5
|
LDL-C (mg/dl)
|
-7±17
|
0.2
|
-15±22
|
0.02
|
0.4
|
Creatinine clearance
|
-16±29
|
0.1
|
-3±29
|
0.9
|
0.2
|
Urine K/Na**
|
+0.6±0.3
|
<0.0001
|
+2.0±0.8
|
<0.0001
|
0.001
|
Urine pH
|
+0.1±0.3
|
0.7
|
+0.8±0.5
|
<0.0001
|
<0.001
|
Urine Ca/Creatinine
|
-2±33
|
0.9
|
-45±43
|
0.002
|
0.008
|
* Bold = p < 0.05.
Underline = p < 0.10
** The urinary
potassium:sodium ratio reflects dietary intake, and therefore can be used as a
marker of compliance. “Calculation of potassium to sodium ratio
confirmed that all the patients, except for one, on the Paleo diet were compliant
with the diet”
Lastly, after the trial was over the participants seemed to revert back to their old diets (based on urine sodium and potassium) and consequently the reductions in cholesterol and HbA1c were also reverting back to the usual level.
The % for protein, fat and carbohydrates total 103.5%? How is that possible?
ReplyDeleteIt could be a mistake. It could also be a poor assumption whereby they measure calories, protein, fat and carbs, then multiply P,F,C grams by 4,9,4 respectively (which in itself may produce minor inaccuracies), which of course slightly overestimates carb % due to fibre, etc. If so, this is a good example where calculating carb % by subtraction could be both simpler and more accurate
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