Sweeteners and sweet taste:
What is the evidence concerning the effects of sugar and
low-calorie sweeteners on energy intake and body weight?
Peter Rogers
School of Experimental Psychology, University of Bristol, UK
ILSI Brasil: IX Updates on Food Safety – Sweeteners. São Paulo, 28th March 2017
Outline
• Some background on appetite and energy balancing
• Results of a systematic review and meta-analysis of effects of
low-calorie sweeteners consumption on energy intake and
body weight
• Some recent studies on effects of exposure to sweet taste on
desire for sweetness, food selection and food intake
Testing the effects of sweetness with calories (sugar)
and sweetness without calories (LCS)
Sweetness and Calories
Sugar
Low-calorie sweeteners
Calories
Water*
Sweetness
*Or equivalent non-sweet food, or nothing
Low-calorie sweeteners: are they helpful in
appetite and weight control?
• By replacing all or some sugar, low-calorie sweeteners
reduce the energy content of foods and especially drinks
1 kcal
210 kcal
How to decrease energy intake – miss a meal
No breakfast
After missing 625 kcal breakfast
Lunch intake ↑ 135 kcal
Total day intake ↓ 495 kcal
Levitsky D. A. (2005) Physiology and Behavior, 86, 623-632
• Daily energy requirement of a moderately active lean person
weighing 65 kg is about 2300 kcal
• Total energy stored in the body is about 75 x daily energy intake
• Fat stores, 55 x daily energy intake
• Protein stores, 20 x daily energy intake
• Carbohydrate stores, <1 x daily energy intake
• glycogen 18 h, free glucose 30 min
Frayn K.N. (2010) Metabolic regulation: A human perspective. Oxford, Wiley-Blackwell
Relative constancy of blood glucose levels during a typical day
Frayn K.N. (2010) Metabolic regulation: A human perspective. Oxford, Wiley-Blackwell
Low-calorie sweeteners: are they helpful in
appetite and weight control?
• By replacing all or some sugar, low-calorie sweeteners
reduce the energy content of foods and especially drinks
• And reduced energy intake in a meal or snack is not fully
compensated for by increased energy intake at the next
or subsequent meals or snacks
Low-calorie sweeteners: are they helpful in
appetite and weight control?
• By replacing all or some sugar, low-calorie sweeteners
reduce the energy content of foods and especially drinks
• On the other hand it has been claimed that consumption
of low-calorie sweeteners may
• confuse the relationship between sweet taste and calories
(and thereby increase sugar and energy intake)
• increase desire for sweetness (and thereby increase sugar and
energy intake)
International Journal of Obesity (2106) 40, 381-394
International Journal of Obesity (2106) 40, 381-394
Effects of low-calorie sweeteners consumption on body weight: animal studies
• Body weight gain when low-calorie sweeteners added to food or drink
compulsorily or voluntarily consumed, compared with body weight gain
on the food or drink without low-calorie sweeteners:
Rogers et al. (2015) International Journal of Obesity, 20, 381-394
Effects of low-calorie sweeteners consumption on body weight: animal studies
• Body weight gain when low-calorie sweeteners added to food or drink
compulsorily or voluntarily consumed, compared with body weight gain
on the food or drink without low-calorie sweeteners:
68 studies:
22↓
37→
9↑
Rogers et al. (2015) International Journal of Obesity, 20, 381-394
Effects of low-calorie sweeteners consumption on body weight: animal studies
• Body weight gain when low-calorie sweeteners added to food or drink
compulsorily or voluntarily consumed, compared with body weight gain
on the food or drink without low-calorie sweeteners:
68 studies:
22↓
37→
9↑
• Body weight gain when low-calorie sweeteners added to a dietary
supplement compared with BW gain when glucose added to the same
dietary supplement:
Rogers et al. (2015) International Journal of Obesity, 20, 381-394
Effects of low-calorie sweeteners consumption on body weight: animal studies
• Body weight gain when low-calorie sweeteners added to food or drink
compulsorily or voluntarily consumed, compared with body weight gain
on the food or drink without low-calorie sweeteners:
68 studies:
22↓
37→
9↑
• Body weight gain when low-calorie sweeteners added to a dietary
supplement compared with BW gain when glucose added to the same
dietary supplement:
22 studies:
0↓
3→
19↑
Rogers et al. (2015) International Journal of Obesity, 20, 381-394
Sweet taste as a predictor of food energy (sugar) content
(1) ‘We reasoned that if sweet tastes are normally valid predictors of increased
caloric outcomes,
(2) then exposing rats to sweet taste that is not associated with these outcomes
should degrade this predictive relationship
(3) and impair energy intake and body weight regulation.’
(Swithers et al., 2010, p 56)
Swithers et al. (2010) Physiology and Behavior, 100, 55-62
Sweet taste as a predictor of food energy (sugar) content
Unsweetened yogurt 3 d/wk
Sweetened yogurt 3 d/wk
Non-predictive (of additional calories) = Saccharin
OR
Predictive (of additional calories) = Glucose
Rat chow ad libitum
Sweet taste as a predictor of food energy (sugar) content
Saccharin
Glucose
Swithers et al. (2010) Physiology and Behavior, 100, 55-62
Boakes et al. (2016) Appetite, 105, 105-128
Sweet taste as a predictor of food energy (sugar) content
(1) ‘We reasoned that if sweet tastes are normally valid predictors of increased
caloric outcomes,* [THIS IS NOT TRUE]
(2) then exposing rats to sweet taste that is not associated with these outcomes
should degrade this predictive relationship
(3) and impair energy intake and body weight regulation.’
*‘In nature, and throughout most of our evolutionary history, sweetness has been a
reliable predictor of the energy content of food.` (Swithers et al., 2010, p 56)??
Swithers et al. (2010) Physiology and Behavior, 100, 55-62
Sweet taste predicts the sugars but not the energy content of
foods and drinks
Sugar content does not predict energy content of ‘natural’ foods
Some individual fruits
Strawberry = 8 g sugar
Blueberry = 14 g sugar
Grape =
17 g sugar
International Journal of Obesity (2106) 40, 381-394
Low-calorie sweeteners consumption: prospective cohort studies (BMI)
Rogers et al. (2016) International Journal of Obesity, 40, 381-394
Cause or effect?
International Journal of Obesity (2106) 40, 381-394
Short-term effects of sugar and sweetness on energy intake
‘Preload’
= <1 kcal
‘Test meal’
1500 kcal served
Total energy
intake
900 kcal
Hypothetical results based Rogers et al. (2016) International Journal of Obesity, 40, 381-394
Short-term effects of sugar and sweetness on energy intake
‘Preload’
= <1 kcal
150 kcal
900 kcal
975 kcal
‘Test meal’
1500 kcal served
Total energy
intake
‘Compensation’
= 50%
Hypothetical results based Rogers et al. (2016) International Journal of Obesity, 40, 381-394
Short-term effects of sugar and sweetness on energy intake
‘Preload’
= <1 kcal
150 kcal
= 0 kcal
900 kcal
975 kcal
900 kcal
‘Test meal’
1500 kcal served
Total energy
intake
‘Compensation’
= 50%
Hypothetical results based Rogers et al. (2016) International Journal of Obesity, 40, 381-394
Effects of consuming low-calorie sweeteners on short-term energy intake
Preload, test-meal studies showed:
• Reduced energy intake versus sugar
Rogers et al. (2016)
International Journal of Obesity, 40, 381-394
More details of short-term
intervention studies results:
‘compensation’ (COMPX) scores
Preload, test-meal studies showed:
• Reduced energy intake versus sugar
(70% compensation in children)
(43% compensation in adults)
(50% compensation overall)
Rogers et al. (2015) International Journal of Obesity,
doi: 10.1038/ijo.2015.177
Effects of consuming low-calorie sweeteners on short-term energy intake
Preload, test-meal studies showed:
• Reduced energy intake versus sugar
• No difference in energy intake
versus water
Rogers et al. (2016)
International Journal of Obesity, 40, 381-394
International Journal of Obesity (2106) 40, 381-394
Sustained intervention studies:
effects of low-calorie sweeteners versus sugar on body weight
Rogers et al. (2016) International Journal of Obesity, 40, 381-394
Sustained intervention studies:
effects of low-calorie sweeteners versus water on body weight
Rogers et al. (2016) International Journal of Obesity, 40, 381-394
Sustained intervention studies:
effects of low-calorie sweeteners on energy intake
• Low-calorie sweeteners versus sugar: -75 to -514 kcal/d (9 studies)
• Low-calorie sweeteners versus water: -126 kcal/d (1 study)
Rogers et al. (2016) International Journal of Obesity, 40, 381-394
Low-calorie sweeteners: are they helpful in
appetite and weight control?
• By replacing all or some sugar, low-calorie sweeteners
reduce the energy content of foods and especially drinks
• On the other hand it has been claimed that consumption
of low-calorie sweeteners may
• confuse the relationship between sweet taste and calories
(and thereby increase sugar and energy intake)
• increase desire for sweetness (and thereby increase sugar and
energy intake)
Does consumption of low-calorie sweeteners
increase or decrease desire for sweetness?
Repeated exposure to sweetness engenders
preference for sweetness.
e.g., Mattes & Popkin (2009) American Journal of
Clinical Nutrition, 89, 1-14
“In addition, overstimulation of sugar receptors by
frequent consumption of hyper-intense
sweeteners may cause taste preferences to remain
in, or revert to, an infantile state (i.e., with limited
tolerance to more complex tastes).”
Ludwig, D.S. (2009) Journal of the American
Medical Association, 302, 2477-8
Yang, Q. (2010) Yale Journal of Biology
and Medicine, 83, 101-8
Does consumption of low-calorie sweeteners
increase or decrease desire for sweetness?
Repeated exposure to sweetness engenders
preference for sweetness.
e.g., Mattes & Popkin (2009) American Journal of
Clinical Nutrition, 89, 1-14
“In addition, overstimulation of sugar receptors by
frequent consumption of hyper-intense
sweeteners may cause taste preferences to remain
in, or revert to, an infantile state (i.e., with limited
tolerance to more complex tastes).”
Ludwig, D.S. (2009) Journal of the American
Medical Association, 302, 2477-8
And/or Sensory-Specific Satiety?
Hetherington M.M. et al. (1989) The time course
of sensory-specific satiety. Appetite, 12, 57-68.
Yang, Q. (2010) Yale Journal of Biology
and Medicine, 83, 101-8
Consuming a low-calorie sweet drink reduces desire to consume sweet foods
Effect of consuming sweet (water) versus non-sweet (low-calorie blackcurrant
squash) drinks on desire to consume apple juice, fresh apple and apple pie
Effect of Drink, p=.003
Effect of Stimulus, p=.002
Drink x Stimulus, F<1
Rogers et al., unpublished data
Participants randomised to
choose water (n=106) or
diet beverages (n=104) in
place of sugar-sweetened
beverages for 6 months.
Low-calorie sweeteners: are they helpful in appetite
and weight control? Conclusions
• By replacing all or some sugar, low-calorie sweeteners reduce the
energy content of foods and especially drinks – leading to reduced
energy intake and body weight
• On the other hand it has been claimed that consumption of low-calorie
sweeteners may
• confuse the relationship between sweet taste and calories (and thereby
increase sugar and energy intake) – (1) there is no evidence for this in humans,
and (2) there are logical problems with this argument and (3) the relevant
results from animal studies have recently been disputed
• increase desire for sweetness (and thereby increase sugar and energy intake) –
if anything, in the short-term exposure to a sweet drink decreases desire and
intake of sweet food
Sustained intervention studies: further results
Blinding
• Outcomes were similar whether or not participants were ‘blinded’ to the
intervention (i.e., whether they were aware or not aware they were
consuming reduced calorie products)
Addition versus substitution
• Outcomes were similar for studies in which (1) the test products were
added to the diet, compared with (2) when participants were already
consuming sugar-sweetened products and the intervention was (partial)
replacement of sugar with low-calorie sweeteners
Rogers et al. (2016) International Journal of Obesity, 40, 381-394
Is there generalisation of sensory-specific satiety
from a sweet drink to sweet foods? An intake study
Cross-over design
Participants consumed the drink with a
sandwich and with the subsequently
presented Doritos (savoury) and
chocolate chip cookies (sweet).
Diet Coke vs water
• Doritos, ns
• Chocolate chip cookies, p=.024
Effect of reducing dietary intake of simple sugars on perceived sweet
taste intensity and pleasantness
Month 1: Baseline
Months 2-3:
Low-sugar diet group (n=13) replaced 40% of
calories from simple sugars with fats, proteins
and complex carbohydrates
Control group (n=16) did not change their
sugar intake
Month 5: Both groups ate what they wished
Wise et al. (2016) American Journal of Clinical Nutrition, 103, 50-60
Effect of reducing dietary intake of simple sugars on perceived sweet
taste intensity and pleasantness
Sweetness intensity
Sweetness pleasantness
Wise et al. (2016) American Journal of Clinical Nutrition, 103, 50-60
Sweetness and energy balance
Effect on body weight (kg) of iso-energetic
exchange of free-sugars with other CHOs
or other macronutrients
Morenga et al. (2012) British Medical Journal, 345, e7492
Disclosures
• I have received funding for research from Sugar Nutrition UK, provided
consultancy services for Coca-Cola Great Britain and received speaker’s
fees from the International Sweeteners Association.
• I will be referring to a systematic review and meta-analysis of effects of
low-calorie sweeteners on energy intake and body weight. This review was
initiated by ILSI-Europe, who also provided administrative support, hosted
meetings of the authors, and paid the academic authors travel expenses
and honoraria. Two of the eleven authors of the review are food industry
employees, and one was an ILSI-Europe employee.