Tuesday, May 31, 2016

Paleolithic Diet Trials: Otten et al


* The paper is behind a pay wall.  I have access, but if you don’t some of the data is in a supplementary document that you can access here (just remember that the data is in median, interquartile range)

Methods

32 older people with a BMI 25-40 and type 2 diabetes were randomly allocated to follow either a Paleo diet or a Paleo diet + an exercise program for 12 weeks

“The diet was based on consuming lean meat, fish, seafood, eggs, vegetables, fruits, berries, and nuts. Cereals, dairy products, legumes, refined fats, refined sugars, and salt were excluded with the exception of canned fish and cold cuts like ham. The diet was consumed ad libitum, with restrictions of the following: eggs (1–2/day but a maximum of 5/week), potatoes (1 medium sized/day), dried fruit (130 g/day), and nuts (60 g/day). Rapeseed or olive oil (maximum 15 g/day) and small amounts of honey and vinegar were allowed as flavoring in cooking. Participants were instructed to drink mainly still water. Coffee and tea were restricted to a maximum of 300 g/day, and red wine to a maximum of one glass/week”

“…all study participants were advised to perform moderate exercise (e.g. brisk walking) for at least 30 min every day. The PD-EX group underwent a program comprising a combination of aerobic exercise and resistance training in 1-h sessions three times weekly”

Results

The reported energy intakes at baseline are a lot lower than the baseline energy expenditure (2995 and 2960 kcal), suggesting some serious underreporting is going on.  See table 3 for more results, bold indicates a significant difference


Paleo
Paleo + Exercise
Baseline
12 weeks
Baseline
12 weeks
Energy
2022
1731
1595
1065
Protein
83 (17%)
96 (24%)
77 (18%)
79 (26%)
Fat
88 (39%)
71 (42%)
67 (34%)
61 (45%)
Carbohydrate
200 (41%)
127 (31%)
169 (42%)
77 (27%)
Fibre
21
23
20
14

Both groups experienced significant weight loss and improvements in many metabolic markers.  Despite decreasing SFA and increasing MUFA and PUFA, LDL-C wasn’t altered by the diet or exercise, which might be due to high statin use (6/15 and 8/14) and the already low LDL-C

The Paleo + exercise group had identical weight loss with minimal differences in body composition vs. the Paleo group.  The exercise group had a non-significant larger reduction in fasting glucose, but started significantly higher, and slightly larger reduction in HbA1c, but 0.2% is not that exciting. As Adel Moussa points out, the real benefit to the exercise intervention is an increase in fitness (VO2 max and heart rate), which can become quite important for the day-to-day functioning of these older participants.  But a possible explanation as to why the exercise intervention didn’t have more effect is that the physical activity energy expenditure (measured from accelerometer and heart rate monitor over a 7 day period) didn’t change in the Paleo + exercise group (-18 (-368, 340) kcal), so perhaps there was some compensation as a result of the intervention.  See table 2 for more results, bold indicates a significant difference


Paleo
Paleo + Exercise
Baseline
Change
Baseline
Change
Weight (kg)
90.0
-7.1
97.3
-7.1
Body fat (%)
37.8
-3.5
37.7
-4.1
Lean mass (kg)
56.5
-1.4
61.0
-1.2
WC (cm)
111
-9
108
-8
HbA1c (%)
7.1
-0.9
7.3
-1.1
Fasting glucose (mmol/l)
8.0
-0.9
8.9
-2.0
Fasting insulin (mIU/l)
23
-8
16
-4
VO2 max
23.4
1.9
22.5
3.3
Resting heart rate
70
-3
72
-11
Systolic blood pressure
135
-17
132
-11
Diastolic blood pressure
86
-9
82
-10
Total-C (mmol/l)
4.2
-0.3
4.3
-0.6
HDL-C (mmol/l)
0.85
-0.01
1.09
0.01
LDL-C (mmol/l)
2.1
-0.1
2.4
-0.1
Triglycerides (mmol/l)
2.1
-0.6
1.7
-0.5
hsCRP (mg/l)
1.2
-0.4
1.5
-0.4

Also, check out Adel Moussa’s article on this study at SuppVersity

Paleolithic Diet Trials: Genoni et al


Methods

39 overweight and healthy middle-aged women were randomised to follow a Paleolithic diet of the Australian Guide to Healthy Eating (AGHE) for 4 weeks.  Both diets were ad libitum

“Those in the Paleolithic group were provided with meal ideas obtained from “The Paleo Diet” book and advised to consume lean meats, fish, eggs, nuts, fruits and vegetables, and small amounts of olive or coconut oils. Grains, cereals and dairy products were not permitted. Dairy products were replaced with unsweetened almond milk. Sugarless black coffee and tea were allowed. All vegetables were permitted on the diet, except for corn, white potatoes and legumes. To ensure adequate carbohydrate, additional fruit was recommended. Dried fruit was limited to one tablespoon per day”

“The AGHE group were counselled on how to achieve food variety in line with the five food groups and Australian dietary recommendations; increasing vegetable and fruit intake and whole grain products, reducing fat intake, and consuming low fat dairy products. Advice was also given to reduce intake of discretionary food items such as cakes, biscuits, sugary drinks and candy. Subjects received the AGHE plate poster and fridge magnet”

Results

The Paleo group significantly reduced their energy intake by 24% while the AGHE group reduced their energy intake by 18% and this was near significant.  Protein as a % of total energy intake significantly increased in the Paleo group but absolute intake only increased from 90.2 to 91.2 grams.  Fibre intake wasn’t altered by either diet.  This may initially suggest poor compliance, but it should be remembered that the average energy intake of both groups decreased a fair bit and fibre intake was quite reasonable to begin with (~25g). See table 3 for more results, bold indicates a significant difference


Paleo
AGHE
Δ vs Groups
Pre
Post
Δ
Pre
Post
Δ
Energy intake (kJ)
7798
5915
−1883
8088
6657
−1432
−451
Protein (%)
20.6
26.8
6.19
20.1
21.7
1.52
4.67
Fat (%)
33.6
39.8
6.20
35.8
32.6
−3.20
9.39
Carbohydrate (%)
39.1
27.8
−11.3
37.2
40.6
3.34
−14.63

Contrary to previous studies, differences in micronutrient intake were very mixed, with no diet being clearly superior to another.  The Paleo group improved their intakes of vitamins A, C and E and to a greater extent than the AGHE group, but significantly reduced their intake of thiamine, riboflavin (quite surprising considering main sources of riboflavin are animal foods and veg) and calcium (and iodine and sodium most likely due to the low salt recommendations in 'The Paleo Diet' book).  However, it’s important to remember that the Paleo group were consuming 11% fewer calories (see table 4)  

Unsurprisingly, the Paleo group lost significantly more weight, fat mass, and waist size compared to the AGHE group, though more than you might expect.  Total cholesterol and LDL-C were significantly reduced in both groups, which is not surprising as both groups significantly reduced their intake of saturated fat.  Systolic blood pressure, diastolic blood pressure, fasting glucose and insulin weren’t affected at all by either diet, but were already good to begin with (average blood pressure < 120/80, glucose < 5 mmol/l and insulin < 5 mU/L).  Serum β-carotene and red blood cell folate significantly increased in the Paleo group and to a greater extent than the AGHE group, the β-carotene can be easily explained with the very large increase in β-carotene intake, but folate actually significantly decreased in the Paleo group (a possible explanation is that vitamin B12 can improve folate status?).  See table 1 and 2 for more results, bold indicates a significant difference


Paleo
AGHE
Δ vs Groups
Pre
Post
Δ
Pre
Post
Δ
Body weight (kg)
73.8
70.6
−3.20
73.0
71.8
−1.21
−1.99
Fat mass (kg)
26.2
24.1
−2.14
23.6
23.1
−0.46
−1.68
Fat free mass (kg)
48.5
47.1
−1.38
50.2
49.4
−0.79
−0.59
WC (cm)
85.9
82.5
−3.35
83.0
81.4
−1.55
−1.90

It’s nice to see another Paleo trial and one from Australia too.  Besides micronutrient intakes, this trial didn’t find much more than significantly better weight loss in the Paleo group after 4 weeks.  Obviously, a limitation is that this trial is only 4 weeks long and therefore adherence should still be quite high.  4 weeks is long enough to see changes in things like blood lipids, blood pressure, and glucose/insulin but the latter two didn’t happen because the participants were already quite healthy, just a little overweight

Paleolithic Diet Trials: Jonsson et al (Part 2)


This paper was published recently and adds some more data to the Jonsson Paleo diet trial, which I have previously blogged about here

To summarise, the Jonsson trial was a randomised crossover trial (3 months each) with 13 patients that had type 2 diabetes, where a Paleo diet was compared conventional dietary advice for diabetics [1]


Paleolithic diet
Diabetes diet
Higher in each diet
Fruits, vegetables, meat, eggs
Potatoes, cereals without rice, milk/milk products
Energy (kcal)
1581
1878
Protein: fat: carbohydrate
24:39:32
20:34:42

The Paleo group lost more weight and some metabolic markers were significantly more improved compared to the diabetes diet (HDL-C, triglycerides, DBP, HbA1c), but not others (SBP, glucose, measures of insulin resistance) (table 3) [1]

A follow-up study looked at the satiety and subjective experiences (see link for responses) of the participants and found satiety to be equal but satiety per calorie to be higher on the Paleo diet [2]

This study looked various hormones and found that only leptin was significantly different, though glucagon was near significant (see table 2 for more).  The significant difference in leptin is not that surprising considering the Paleo diet resulted in significantly more weight loss than the diabetes diet


Palaeolithic diet
Diabetes diet
Delta diets
p
Leptin
(ng/ml)
5.1 ± 4.9
(2.1 to 8.0)
7.4 ± 8.3
(2.4 to 12)
−2.3 ± 4.6
(−5.1 to 0.4)
0.023
Insulin
(pg/ml)
248 ± 138
(165 to 332)
336 ± 327
(138 to 533)
−87 ± 240
(−232 to 58)
0.266
Glucagon
(pg/ml)
409 ± 40
(385 to 433)
431 ± 51
(400 to 463)
−22 ± 43
(−48 to 3.9)
0.089

They then looked at correlations between hormones with other hormones, metabolic markers and nutrients with the significant correlations being listed in table 3.  With this kind of data I place more value on the correlations between hormones and metabolic markers rather than nutrients, as the former can potentially inform on the biological mechanisms (for example there are significant correlations between glucagon and some of the insulin measurements (unsurprisingly), although leptin wasn’t significantly correlated with weight loss), while the latter is really just an observational study within an RCT (and you can sometimes find just about anything depending on the intervention)