Transcript The use of low carbohydrate diet in the management of Type 2

The use of low carbohydrate diets
in the management of Type 2
diabetes
Changes in Diabetes Dietary Guidelines
Nutrient
1930’s
1970’s
1980’s
1990’s
2000’s
CHO
% of Energy
15%
40%
>50%
50-55%
60-70%
With MUFA
Protein
% of Energy
17%
45%
15%
10-15%
10-15%
Fat
% of Energy
68%
15%
<35%
30-35%
<35%
Added
Sucrose
None
None
A little
mixed diet
<25g/day
<10%
Current Recommendations
• Little evidence for the ideal macronutrient composition in the
management of hyperglycaemia
• Great flexibility and consumption of macronutrients based on
RI for healthy eating is encouraged
• Looking at different diets (low CHO, low fat) small and
inconsistent differences regarding weight loss. Adherence is
the important factor.
Casting Doubt on Carbohydrate
Feinman et al 2014
• Restriction of CHO decreases blood glucose levels
reducing hyperglycaemia
• During increase in obesity and T2 DM, calories have
increased due to CHO intakes
• See benefits of reducing CHO without requiring wt
loss
• Adherence to low carb diets is as good as other diet
interventions
• Replacement of CHO with protein is beneficial
• Total and sat fat do not correlate with CVD
Feinman et al, Dietary Carbohydrate Restriction as the first approach in diabetes management. Nutrition and
Metabolism, 2014.10.1186/1743-7075-5-9
Feinman et al 2014 cont’d
• Plasma sat fatty acids are controlled by CHO more than
diet lipids
• Best predictor of Microvascular and to smaller degree
macrovascular in T2 DM is glycaemic control
• Restricting CHO is the most effective method of
reducing TG and increasing HDL
• Patients with T2 DM on CHO restricted diets reduce
and eliminate medication. T1 DM require less insulin
• Intensive glucose lowering by CHO restriction has no
side affects comparable to medication
How much Carbohydrate?
• Moderate carbohydrate: 130 to 225g of carbs
(26 – 45% of Energy)
• Low carbohydrate: under 130g of carbs (<26%
of Energy)
• Very low carbohydrate: under 30g of carbs
(<10% of Energy)
Evidence for Low Carb diets
Trudi Deakin
• Current recommendations do not control epidemic of
diabetes, 50% of calories from CHO is not beneficial
• Failure of low fat diets to improve obesity, cardiovascular risk
or general health
• Side affects of commonly prescribed medication
• Evidence that low carb diets are successful without side
affects
• Carbohydrate requirements differ based on individual
preference, body weight, diabetes control, insulin resistance
and physical activity levels;
• People need carbohydrate awareness education so that they
can assess their carbohydrate intake and set goals to meet
their individual needs.
Does a low fat diet help?
• Diet- Heart theory has never been proven. 2/3rds people
admitted to hospital with MI have normal cholesterol
• Current evidence does not support high consumption of PUFA
and low SFA
• Small dense particles of LDL – increase risk of CHD. Excess
consumption of CHO leads to small dense LDL (de novo
lipogenesis)
• Low fat diet decreases blood lipids but concern reduces large
LDL cholesterol and HDL not small dense LDL
• Low fat diet have not decreased prevalence of obesity and T2
DM
• Eating unprocessed foods containing SFA, MUFA and Omega 3
from fish but avoid trans fat, PUFA and excessive high GI foods
has been shown to help health status
Example of very low carb diet
• Breakfast: 1 fried egg, 2 rashers of bacon, grilled
tomato, fried mushrooms in butter
Coffee/tea with milk allowance
• Lunch: Mackerel fillets, salad, 1 tbsp mayo, almonds
• Evening meal: ¼ roast chicken, broccoli and carrots.
Gravy from meat juices
Sugar free jelly with whipped cream and fruit
• Supper: glass of red wine, 50g cheese
• Milk in drinks: 200mls full fat
1875 kcals, Fat: 135g (65%), CHO: 36g (8%)
Evidence against Low carb diets
Carla Gianfrancesco
• Reducing carbohydrate reduced healthy CHO which have
been shown to protect against heart disease
• A restricted carbohydrate diet results in an unbalanced diet
• Low carb diets leads to the production of Ketones - ? Long
term effect
• Brain prefers glucose as a fuel, needs 130g per day
• No conclusive evidence that low carb diets are better - ?
Adherence
• Teaching carb awareness is beneficial help people enjoy a
variety of CHO
Diabetes UK response
• Use an individualised approach
• People need to understand what foods
contain CHO, how to estimate CHO portions,
monitor effects on BG
• Aim to obtain CHO from vegetables, fruit,
wholegrains and dairy
What does BHF advise?
• Whilst the latest study didn’t show saturated fat
is associated with cardiovascular disease, it also
didn’t show that eating more of it is better for
your heart health.
• Eating a diet rich in fruit and vegetables, pulses,
beans, wholegrains, unsaturated oils and fish
means there is less room for the foods high in
saturated fat and salt like fatty or processed
meats and sweet treats.
• We need to think about the overall balance of the
food and nutrients
Dietary fat consumption in the management of type 2
diabetes (Diabetes UK and DMEG)
• Replacing SFA with PUFA and MUFA reduces the risk of CVD in general
populations and in high-risk populations including people with type 2
diabetes.
• When saturated fat intake is replaced by wholegrain/unrefined
carbohydrates there is evidence for cardiovascular benefit. Refined
carbohydrates appears to increase cardiovascular risk.
• No evidence suggesting increasing SFA intake is beneficial in reducing risk
of CVD.
• Evidence suggests that Mediterranean-type (MUFA-rich) diets are
effective for improving glycaemic control and CVD risk in people with type
2 diabetes.
• Low carbohydrate diets, which are not high in SFA, and other diets that are
evidence-based options for the management of type 2 diabetes can
continue to be recommended for weight loss under appropriate dietetic or
medical supervision on an individual basis.
Conclusion
• Researchers can’t agree - ? Will policy change
• Use an individualised approach with patients.
Focus on food rather than single nutrient
• Review patient’s CHO intake and if obese/ poor
glycaemic control then makes sense to reduce
CHO intake
• Patient choice of going on a low carb diet –
ensure that they are aware of the side affects
• Promote unprocessed foods - Mediterranean
style diet