Outline of presentation
School of Life Sciences
Structured lipids for
weight loss
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Geoff Talbot
The Fat Consultant
Visiting Fellow, Oxford Brookes University
What are structured lipids?
How can they be produced?
Structured lipids for weight loss
• Pine nut based lipids
• Conjugated linolenic acid based lipids
• Diacylglycerols
• Medium chain triglycerides (MCT)
• Reduced calorie fats
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Structured lipids
Uses of structured lipids
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Naturally occurring oils and fats are based on triacylglycerols (TAG)
These contain three fatty acid groups containing (mainly) C12 to C18
chain lengths
• Exceptions:
• Milk fats and coconut oil (shorter chain lengths)
• Fish oils (longer chain lengths)
Structured lipids are TAG in which specific fatty acids have been placed
at specific positions on the glycerol backbone of the TAG
This is done in order to confer specific functional, nutritional or medical
properties
Structured lipids in general have a wider role than being used for
weight loss
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Functional uses
• Margarine fats
• Plastic fats for margarine bases
• Hardstocks to structure margarine
• Cocoa butter equivalents
• StOSt TAG
Nutritional uses
• Enteral and parenteral nutrition
• Combinations of medium chain and long chain fatty acids
• Infant nutrition
• TAG with C16:0 in the sn-2 position to mimic breast milk
• Weight loss – or weight management
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What do I mean by structured lipids?
Random interesterification
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Catalysis
• Chemical – sodium, sodium alkoxide
• Enzymatic
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Although distribution of fatty acids is fully random it is also highly
predictable
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If the total fatty acid composition is known then the total breakdown in
terms of TAGs can be calculated
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First point to make
• Although in the main, lipids will be taken to mean triacylglycerols
(TAG), the term covers many more structures
• Free fatty acids will be considered in the context of weight
management
Second point to make
• Most ‘structured lipids’ are in the form of TAGs in which specific
fatty acids are at specific positions on the TAG molecule
So – how are structured TAGs produced?
• Mainly by a process called interesterification – either random or
specific
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How are structured lipids produced?
Specific interesterification
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Interesterification
• Random interesterification
St
St
St 50%
St
Na
catalyst
+
•
O
O 50%
O
St
St
St
St
12.5%
O
St
O
12.5%
O
St
St
12.5%
O
O
O
12.5%
St
O
O
12.5%
P
P
St
12.5%
St
O
St
12.5%
If an enzyme is used as the catalyst then a more specific type of
interesterification can occur
For example, certain lipases will only allow fatty acids in the 1- and 3positions to interchange, leaving any fatty acids in the 2-position in their
original places
P
1,3-specific
enzyme
+
O
O
Oleic acid
O
12.5%
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P
P
O
O
+ oleic acid
+ palmitic acid
0
Pinnothin
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Italian pine
nut oil
Linoleic
acid
CLA
Source: LipidNutrition
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CCK and GLP-1 release during 4 hours after
consumption of Pinnothin™ or placebo
Pinnothin™ is now GRAS approved
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CCK
GLP-1
250
2500
200
2000
150
1500
100
1000
50
500
0
Placebo
Pinnothin
Source: LipidNutrition
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O
P
180
They are appetite-suppressants rather than weight loss lipids but can
be considered to function as such by reducing the desire to eat
They can be consumed either as the free fatty acids or in a triglyceride
form
Commercially they are marketed as Pinnothin™ by LipidNutrition
Placebo Pinnothin
P
P
Effect of Pinnothin™ on CCK release
Nuts from the Korean pine tree [pinus koraiensis] are rich in pinolenic
acid
Pinolenic acid is an omega-6 triunsaturated fatty acid [C18:3 - 5,9,12]
Pinolenic acid stimulates the release of CCK (cholecystokinin) and
GLP1 (glucagon-like peptide 1)
These both send signals of satiation to the brain
0
O
P
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Pine nut based lipids
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P
P
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After having self-determined GRAS status, Pinnothin™ has recently
been GRAS approved by the FDA
Potential food applications are:
• baked goods and baking mixes,
• beverages and beverage bases,
• breakfast cereals,
• dairy product analogs,
• fats and oils,
• grain products and pasta,
• fluid milk and milk products,
• nuts and nut products,
• processed fruit and fruit juices,
• processed vegetables and vegetable juices,
• snack foods,
• soft candy
• soup & soup mix applications
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Conjugated linoleic acid (CLA)
Conjugated linoleic acid
COOH
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Linoleic acid (C18:2 c9, c12)
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COOH
Naturally occurring in the meat and milk of ruminant animals
Produced by biohydrogenation of linoleic acid in the rumen
As meat and milk consumption has decreased so has consumption of
CLA
Available as supplements
Also available in food form
Conjugated linoleic acid (C18:2 c9, t11)
COOH
Conjugated linoleic acid (C18:2 t10, c12)
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CLA in margarine
Effect of CLA on body fat mass
60% CLA/40% palm stearin
FA Compn of margarine
enzymatic
interesterification
50% ei(CLA/PS)/50% palm superolein
C14:0
0.8%
C16:0
30.2%
C18:0
2.9%
C18:1
39.0%
blend
C18:2
12.4%
emulsify
C18:3
1.9%
CLA
10.6%
SFC of margarine
Margarine
25
EM5 – exptl marg/5C
EM15 – exptl marg/15C
CM5 – comm marg/5C
CM15 – comm marg/15C
20
Source: Goli et al,
JAOCS 86 453-458
% solid fat
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Meta analysis* of 16 peerreviewed, double blind,
placebo-controlled studies:
• CLA reduced body fat in
a dose dependent
manner
• 3.2g CLA per day
resulted in 90g fat mass
loss per week
Change in fat mass over 6 months
*Whigham et al, Am. J. Nutr. 85,
1203-1211
5
0
EM5
EM15
CM5
CM15
Change in lean body mass
Source: LipidNutrition
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Diacylglycerols (DAG oils)
Diacylglycerols (DAG-oils)
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Most oils and fats contain some (typically 2-10%) DAG
DAG oils are lipids rich in 1,3-DAG and 1,2-DAG – containing typically
about 80% total DAG
Launched commercially in Japan by Kao Corporation and in the USA
and Europe by ADM under the brand name ENOVA™
Digested and absorbed like TAG
Metabolised differently
• Converted directly into energy instead of accumulating as fat in
adipose tissue
• Lower serum TAG
Potential for use in reducing saturates in food
Shown to reduce body weight
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Nagao et al (J. Nutr.
130, 792-797
• Fed volunteers
two diets each
containing 50g
total fat/day (15g
at breakfast, 15g
at lunch, 20g at
dinner)
• One group
received 10g TAG
oil rich meal at
breakfast; the
other group 10g
DAG oil-rich meal
Visceral fat area
Total fat area
TAG-oil
DAG-oil
Waist
BMI
Body weight
-30
-20
-10
0
% change over 16 weeks
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Medium-chain triglycerides (MCT)
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Production of MCT
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short-chain
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medium-chain
long-chain
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MCT – absorbed directly into portal circulation and transported to liver for
rapid oxidation
Mainly derived from coconut
oil
Oil is hydrolysed into
constituent free fatty acids
C8 and C10 are isolated by
distillation
C8 and C10 re-esterified on
to glycerol to produce a
reconstituted triglyceride
LCT – transported by chylomicrons into lymphatic system allowing
extensive uptake into adipose tissue
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Weight loss and Energy Expenditure studies on MCT
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Fatty acid composition of
coconut oil
C6:0
1.3
C8:0
12.2
C10:0
8.0
C12:0
48.8
C14:0
14.8
C16:0
6.9
C18:0
2.0
C18:1
4.5
C18:2
1.4
C20:0
0.1
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Effect of MCT and olive oil diets on body weight
St-Onge and Jones (J. Nutr. 132, 329-332)
• Replacing LCT with MCT increases daily EE from 100 to 669 kJ/d
in men and to 138kJ/d in women
• Energy intake 1079kJ lower with MCT diet compared to LCT diet
• Would result in an avoidance of 0.45-1.35kg/mo weight gain on
MCT diet compared to LCT diet
St-Onge and Bosarge (Am J Clin Nutr 87 621-626)
• Compared diets containing 18-24g/d of MCT oil or olive oil over 16
week period
olive oil
MCT oil
Source: St-Onge and Bosarge (Am J Clin Nutr 87 621-626)
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Effect of MCT and olive oil diets on fat mass and lean
tissue
end point
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Disadvantages of MCT oils for weight loss
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Source: St-Onge and Bosarge (Am J Clin Nutr 87 621-626)
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Unfavourable effect on blood lipids (Thorstrup, 2004)
• Compared with oleic acid in a 21 day diet MCT oils resulted in
• 11% higher total cholesterol
• 12% higher LDL cholesterol
• 32% higher VLDL cholesterol
• 12% higher LDL:HDL cholesterol ratio
• 22% higher blood triglycerides
Very high in saturates (almost 100%) and deficient in essential fatty
acids
• Cannot be used as the only lipid source in the diet
• Structured MLCT (medium and long chain triglycerides) can be
used to obtain some of the benefits of MCT while, at the same time,
introducing EFAs (especially n-3 fatty acids)
Weight loss is less for females than for males
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Structured MLCT lipids
Other combinations
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Most published information on other combinations is on the methodology of
production and the structure of the lipids rather than on their effects on weight
loss
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Examples:
• Lee and Akoh (JAOCS, 75, 495-499)
• Enzymatically interesterified n-3 LC-PUFA with tricaprylin (2:1)
• Rocha-Uribe and Hernandez (JAOCS, (2004) 81, 685-689)
• Enzymatically interesterified CLA with either tricaprylin or
coconut oil
• Vu et al (Int J Food Sci & Nutr. (2008), 59, 95-104)
• Produced structured DAG containing both CLA and capric acid
groups)
• Lee et al (Ann. Nutr. Metab. (2006), 50, 219-228
• Rat feeding trials of CLA/capric acid structured DAG
• Weights of adipose tissue significantly less in structured DAG
than in conventional (long-chain) DAG oil
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To overcome some of the issues associated with MCT oils some
studies have looked at MLCT (medium-long-chain structured TAGs)
Matsuo et al (BJN (2004), 91, 219-225
• Rats fed soyabean oil or an MLCT from interesterified blend of 20%
MCT/80% rapeseed oil
• Intraabdominal adipose tissue and carcass fat significantly smaller
in rats fed 150-200g/kg of MLCT diet than in rats fed the soyabean
oil diet
Roynette et al (Nutr. Metab. And Cardiovasc. Diseases (2008), 18, 298305)
• Humans fed either olive oil based diet or a MLCT diet based on
high oleic canola (rapeseed) oil interesterified with MCT and then
blended with 6-10% plant sterol esters
• Body weight decreased on both diets – no significant differences
Akoh (US Patent 6369252) – extensive patent on production of MLCT
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Reduced calorie fats
Caprenin™
Reduced calorie fats
Salatrim™ (Benefat™)
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Caprenin™ was developed by Proctor and Gamble as a cocoa butter
substitute
Was used by Mars in Milky Way II launched on US West Coast in April
1992
Contains 4.3 kcal/g
Is a structured lipid produced by random interesterification of behenic
acid (~45%) from fully hydrogenated high-erucic acid rapeseed oil and
~50% capric (C10) and caprylic (C8) acids
Had adverse effects on plasma cholesterol levels (Karupaiah and
Sundram (2007), Nutr & Metab. 4, 16) compared to a diet enriched in
PO/PK or butter
• HDL-C decreased
• TC/HDL-C increased
• TC, LDL-C. TAG unchanged
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But why use structured lipids to lose weight?
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Substitution of saturated with monounsaturated fat
(Piers et al (2003), BJN, 90 717-727
• Why not just change from a diet rich in saturates
to one rich in monounsaturates?
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Saturated fat rather than unsaturated fat has been implicated in the
development of obesity (Storlien et al (1998), Curr Opin Clin Nutr
Metab Care 1 559-563)
Monounsaturates oxidise more readily than saturates and
polyunsaturates (Jones et al (1985), Am J Clin Nutr 42, 769-777)
Is this the reason why a diet rich in monounsaturates is less likely to
result in obesity than one rich in saturates?
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SALATRIM™ - Short And Long-chain Acyl TRIglyceride Molecules
Produced by random interesterification of short-chain acids (C2 to C6)
with stearic acid (C18) from hydrogenated liquid oils
Developed initially by Nabisco
Now marketed by Danisco
Contains 5kcal/g
Adjustment of the fatty acid composition allows a range of melting
points
Cannot be used for frying but has been used in bakery chocolate chips,
bakery doughs, sauces and dips
No effect on blood lipids
In a variant, caproic (C6) and butyric (C4) acids were incorporated by
enzymatic interesterification into triolein rather than tristearin (Formoso
and Akoh (1997), JAOCS, 74, 269-272)
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Volunteers put on to two high fat
(40% en) diets
One high in SFA; one high in
MUFA
Volunteers could choose liberally
from a range of foods within
each diet
Trial lasted for 4 weeks
SFA rich diet:
• 24%en SFA, 13%en MUFA,
3%en PUFA
MUFA rich diet:
• 11%en SFA, 23%en MUFA,
6%en PUFA
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Thank you for your
attention
Geoff Talbot
The Fat Consultant
+44 7850 605719
[email protected]
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