In this

1. In type 2 diabetes, randomisation to
advice to follow a low-carbohydrate
diet transiently improves glycaemic
control compared with advice to
follow a low-fat diet producing a
similar weight loss.
Guldbrand H et al Diabetologia. 2012 May 6.
[Open access]
Page 1 Guldbrand H et al Diabetologia. 2012 May 6 http://twitter.com/pronutritionist

2. Pronutritionist’s background
• In recent meta-analyses low carbohydrate diets have been either
equally effective or better than low fat diets in the treatment of type 2
diabetes (Kirk et al. 2008, Kodama et al. 2009)
• The trials included in these meta-analyses have been short, ie. shorter
than 1 year
• In non-diabetic subjects low carbohydrate diets have either been
equally effective or outperformed low fat diets, when minimum 2 year
trials are considered (Shai et al. 2008, Sacks et al. 2009, Foster et al.
2010, Cardillo et al. 2006)
• The long terms effects on low carbohydate diets on cardiovascular risk
factors, glucose and insulin parameters and weight in diabetes are not
known
Page 2 Guldbrand H et al Diabetologia. 2012 May 6 http://twitter.com/pronutritionist

3. Methods (patients)
• Randomized trial, parallell groups, 2 years
• Primary outcomes: weight, HbA1c
• Secondary outcomes: LDL, HDL, triglyserides, blood pressure
• N=61, type 2 diabetics (BMI ∼33), free living subjects
• Diets were to provide 1600 kcal for females or 1800 kcal for males
(design was not ad libitum)
• Diets
– Carbohydrates 20 E %, ie. Low carbohydrate diet. No restriction on the use of
saturated fat was given
– Carbohydrates 55-60 E %, ie. Low fat diet. The diet followed the Swedish dietary
guidelines for diabetics at time of commencement of the trial and saturated fat was
to be stricted to the level of 10 E %
• Primary care setting, dietitians provided information on diets in group
meetings which took place 4 times (at baseline, 2, 4 and 12 months)
• No food was provided for free
• Insulin, incretin mimetics and oral diabetes drugs were allowed
Page 3 Guldbrand H et al Diabetologia. 2012 May 6 http://twitter.com/pronutritionist

4. Methods (schematic)
Randomization
(ballots)
20 % of energy as carbohydrates, ie. low carb diet
2 years
55-60 of energy as carbohydrates ie, low fat diet
Page 4 Guldbrand H et al Diabetologia. 2012 May 6 http://twitter.com/pronutritionist

5. Results (macronutrients)
Dietary intakes (based on food diaries)
Data are given for all participants who provided complete diet recordsaCompared with baselinebFor change over all time pointscFor change
over all time points (between groups)dDenotes statistically significant difference between changes in the two groupseDenotes statistically
significant difference between groups at baseline
Page 5 Guldbrand H et al Diabetologia. 2012 May 6 http://twitter.com/pronutritionist

6. Results (fats)
Dietary intakes (based on food diaries)
Dietary intakes (based on food diaries)
Data are given for all participants who provided complete diet recordsaCompared with baselinebFor change over all time pointscFor change
over all time points (between groups)dDenotes statistically significant difference between changes in the two groupseDenotes statistically
significant difference between groups at baseline
Page 6 Guldbrand H et al Diabetologia. 2012 May 6 http://twitter.com/pronutritionist

7. Results (weight)
The weight reduction did not differ between the groups (p =0.33
for all time points)
Low carb diet
Low fat diet
7 Guldbrand H et al Diabetologia. 2012 May 6 www.pronutritionist.net

8. Results (HbA1c)
The reduction in HbA1c level was statistically significant within the low-carbohydrate group
(p= 0.005 for all time points), but did not differ between the groups when compared at all
time points (p= 0.76). To convert values for HbA1c in mmol/mol into %, divide by 10.929
and add 2.15
Low fat diet
Low carb diet
8 Guldbrand H et al Diabetologia. 2012 May 6 www.pronutritionist.net

9. Results (lipids and blood pressure)
Results for only those patients who consumed ≤6,694 kJ/day (1,600 kcal/day) for women or ≤7,531 kJ/day
(1,800 kcal/day) for men according to the last diet record at 24 months; 17 patients in the low-fat group and 18 patients in
the low-carbohydrate group.
Data are given for all participants who provided complete diet recordsaCompared with baselinebFor change over all time pointscFor change
over all time points (between groups)dDenotes statistically significant difference between changes in the two groupseDenotes statistically
significant difference between groups at baseline
9 Guldbrand H et al Diabetologia. 2012 May 6 www.pronutritionist.net

10. Results (diverse)
• No patients were lost during the follow up, all were
analysed
• 7 patients did not attend all group sessions (3 low carb
and 4 in low fat group)
• HDL-cholesterol increased by 33% in patients
reasonably compliant with low carb diet (post hoc
analysis)
• Average insulin dose at 6 months was lower in low carb
diet group (p=0,046)
• There were no other significant changes in drug usage
• In neither group the target carbohydrate intake was
reached, ie ≤ 20 E % and 55-60 E %
10 Guldbrand H et al Diabetologia. 2012 May 6 www.pronutritionist.net

11. Pronutritionist’s discussion (1/2)
• Both diets induced similar weight reductions
• HDL –cholesterol was increased in low carbohydrate diet at all time
points. No other significant differences in lipids between groups were
found in spite of radical difference in macronutrient composition of diets
• LDL-cholesterol did not change in either of the groups, even if the intake
of saturated fat was increased in low carbohydrate group from 16 E % to
19 E %
• It is noteworthy that absolute intake fat did not change in low carb (high
fat) group
• Low carbohydrate tended to induce bigger energy deficit than low fat diet,
but the difference between the groups was not significant
Page 11 Guldbrand H et al Diabetologia. 2012 May 6 http://twitter.com/pronutritionist

12. Pronutritionist’s discussion (2/2)
• The study shows that a long term low carbohydrate diet in type 2
diabetes may not reap all the benefits demonstrated in shorter trials
• The study shows that there may not be any metabolic risks in type 2
diabetes related to low carbohydrate diet in spite of the increased intake
of saturated fat
• The incidence of gastrointestinal side effects was not monitored and
remain unknown in diabetes
• The trial has a high clinical relevance because it was run with usual
resources at health care centres in Nordic countries
• This study suggests that low fat and low carbohydrate diets are equally
effective and metabolically beneficial. The choice between the diets might
be done on individual preference
Page 12 Guldbrand H et al Diabetologia. 2012 May 6 http://twitter.com/pronutritionist

13. Please read the whole paper at
Guldbrand H et al
Diabetologia. 2012 May 6.
[Open access]
Guldbrand H et al Diabetologia. 2012 May 6
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14. http://twitter.com/pronutritionist
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http://www.pronutritionist.net
Reijo Laatikainen, Authorized Nutritionist, MBA
Guldbrand H et al Diabetologia. 2012 May 6 14/11/12
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