Embed Size (px)
DESCRIPTION
How a person with diabetes eats is fundamentally a personal decision with no ‘correct’ way to do this; only guidelines to work within and which should be personalised. The popularity of different dietary approaches can wax and wane in the public’s eye, with sometimes similar types of dietary approaches ‘rebranded’ under different names. Low-carbohydrate and Palaeolithic diets are enjoying a large degree of popularity and are capturing the headlines, not just for people with diabetes, but the broader population. Just what the basis of these diets are, how they are promoted and followed, and importantly evidence for a benefit in the management of diabetes is explored in this presentation with practical advice on how they can be sensibly followed and supported by someone if they choose to eat within the broad parameters of these types of dietary patterns.
Citation preview
Nutrition @ DEAKIN
Paleo and low-carbohydrate diets for diabetes: today's fads or tomorrow’s advice?
1
Associate Professor Tim CroweSchool of Exercise and Nutrition Sciences
Deakin University
www.facebook.com/[email protected]@deakin.edu.au
Nutrition @ DEAKIN
Topics to be Covered
1. The rationale for the Paleo diet2. Paleo for diabetes3. Paleo wins and fails4. Low-carb diets: the briefest of overviews5. The best diet for diabetes is…
2
Nutrition @ DEAKIN
What is the Paleo Diet?Based on assumed eating habits of our ancestors in the Palaeolithic period (2.5 million and 10,000 years ago) beforeadvent of agriculture and industry
Based on two central ideas:1. We are genetically adapted to eat
particular kinds of foods2. To stay healthy and avoid the chronic
diseases of modernity we need to eat like our ancestors
Is more of a lifestyle than a diet
3
Nutrition @ DEAKIN
Paleo Diet in a Nutshell
4
Nutrition @ DEAKIN
Paleo for Diabetes?Several small studies showing it may improve insulin sensitivity, weight
and several CVD risk factors in the short-term
Study 1*
• 3 month RCT crossover of 13 patients with T2DM (mean HbA1C 6.6%, 9 yrs duration and on OHAs) of Paleo diet vs ‘standard’ diet for diabetes around dietary guidelines
• Greater improvements on Paleo diet with HbA1C (↓ 0.4 percentage points), and improved TG, diastolic BP, weight (3kg) and waist circumference (4cm) and higher HDL
• Paleo diet lower in energy, CHO, GI, glycaemic load, saturated fat, and calcium
5
*Jӧnsson T et al. Cardiovascular Diabetology 2009;8:35
Nutrition @ DEAKIN
Paleo for Diabetes?Study 2*
• 12 week study of 29 people with IHD and IGT or T2DM
• Randomised to a Paleo or Mediterranean style diet
• Both groups saw a benefit in glucose tolerance and body weight
• Greater benefits in glucose tolerance in Paleo group independent of weight change
• Similar benefits on HOMA-IR• Energy intake was 25% lower in Paleo group• 3 dropouts in Paleo group, none in other group
6
*Lindeberg S et al. Diabetologia 2007;50:1795-1807
Nutrition @ DEAKIN
2-Year Paleo RCT• 70 obese post-menopausal women assigned ad libitum
Paleo diet or Nordic Nutrition Recommendations• 12 group sessions over the study• More fat loss in Paleo group at
6 months, but not 2 years• Greater TG ↓ in Paleo group,
but no other differences in othermetabolic measures
7
Mellberg C et al. Eur J Clin Nutr 2014;68:350-7
Nutrition @ DEAKIN
Paleo Reality• Humans are continually evolving to suit our environment
e.g. lactose tolerance increased with exposure to dairy• What we eat today is drastically different to its Paleo
predecessor• There is no one ‘Paleo Diet’ - varies immensely based on
world region• Humans ate what was available to them out of necessity,
not out of choice
8
Nutrition @ DEAKIN 9
Source: www.scientificamerican.com/article/why-paleo-diet-half-baked-how-hunter-gatherer-really-eat/
Nutrition @ DEAKIN
Paleo Diet: Really?
10
Nutrition @ DEAKIN
Paleo Lifestyle
11
A ‘true’ Paleo lifestyle also includes plenty of physical activity from ‘hunting and gathering’
Nutrition @ DEAKIN
Paleo Pros• Emphasises whole foods, lean proteins, vegetables, fruits, nuts,
seeds, and other healthy fats - a big improvement over the typical Western diet
• In Australia, 1/3 of daily kilojoules* is from foods of little nutritional value (discretionary foods) - not ancestral foods, nor foods that any nutrition expert, regardless of dietary persuasion, would ever recommend
• If a person is dedicated and happy to forgo many wonderful staple foods, they can achieve healthy eating and weight control and potentially improve diabetes control
12
*Australian Health Survey 2011-2012 www.abs.gov.au/ausstats/[email protected]/mf/4364.0.55.007?OpenDocument
Nutrition @ DEAKIN
Paleo Cons• There is no single ‘Paleo’ diet• Excludes dairy, high fibre grains and legumes (evidence grains
and legumes were eaten from stone tools analysis at Paleo sites)
• Whole grains and legumes improve health through improved blood lipids, better blood glucose control and less inflammation (but refined grains to ↑ inflammation)
• More reliant on meat• Cost• Unhealthy focus on ‘good and bad’ foods
13
Nutrition @ DEAKIN
Paleo itself is EvolvingPaleo lifestyle versus Paleo Diet
• Paleo advocates coming to appreciate and encourage the addition of moderate amounts of starch, dark chocolate, red wine and even some dairy (butter, yoghurt, cheese)
• These additions make life much more pleasant and make healthy eating more attractive and achievable
• This new “leniency” may partly explain why the Paleo diet continues to gain traction in mainstream nutrition circles
14
Nutrition @ DEAKIN
Low-Carbohydrate DietsDefinition? Cover a diverse range of diets, with food choices changing as degree of CHO restriction changes• Can just limit carbohydrates (~40% of energy), restrict to a set
level e.g. 25% of energy or <130 g/day, or aim to be ketogenic at <50 g/day
• ↓ grains, starch, sugar and ↑ fat and protein• Can be effective in short-term studies <6mo, but as degree of
restriction increases, adherence declines• Two 1-year RCT studies*: no superior benefit of low-carb on
weight, lipids and HbA1C
15
*Larsen RN et al. Diabetologia 2011;54:731-740 and Krebs JD et al. Diabetologia 2012;55:905-904
Nutrition @ DEAKIN
The Latest Study• 115 obese adults with T2DM randomised for 24 wk to
hypocaloric low-carb (14% CHO, <50g) or energy matched low-fat diet (53% CHO). Both <10% sat. fat and included exercise
What was similar• Completion rates (~80%), weight loss (~12 kg), BP,
LDL-C and fasting glucoseWhat was different (only in those with HbA1C > 7.8%)
• Better TG, HbA1C (-2.6 vs -1.9), and glycaemic variability changes in low-CHO group
16
Tay JRN et al. Diabetes Care 2014 Epub July 28, 2014 doi: 10.2337/dc14-0845
Nutrition @ DEAKIN
Not Everyone is Average• In all diet comparison studies,
results are averages – some do better and others worse on each diet. How to narrow this down?
• Several studies* indicate that those with insulin resistance may do better on low-CHO diet vs low-fat diet (the opposite is also true!)
17
*Gardner CD. Tailoring dietary approaches for weight loss Int J Obesity Suppl 2012;2:S11-S15
Nutrition @ DEAKIN
The Best Diet for Diabetes?
• Systematic review and meta-analysis of 20 RCTs of 7 different diets followed for >6 months
• Low-CHO, low-GI, Mediterranean, and high protein diets all effective in HbA1c by 0.12-0.5 percentage points with Mediterranean diet showing largest effect size
“Dietary behaviors and choices are often personal, and it is usually more realistic for a dietary modification to be
individualized rather than to use a one-size-fits-allapproach for each person.”
Ajala O et al. Systematic review and meta-analysis of different dietary approaches to the management of type 2 diabetes Am J Clin Nutr 2013;97:505-516
18
Nutrition @ DEAKIN
Practice Implications1. There is no ‘one size fits all’ approach for diet and diabetes2. Different dietary approaches for diabetes travel on different
roads, of varying surface qualities, but arrive at the same destination
3. Just cutting back on sugary foods/drinks, highly refined carbohydrate sources, ↓ serving size of meals and eating more non-starchy vegetables makes a diet low-carb and approaches Paleo too
4. A diet ‘label’ can be a useful handle, but tailor approach to the individual with a firm eye on nutritional quality
19
