Sweeteners and sweet taste: What is the evidence concerning the effects of sugar and low-calorie sweeteners on energy intake and body weight?

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, 28 th 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 Water* Calories Sweetness *Or equivalent non-sweet food, or nothing

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

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 Test meal 1500 kcal served Total energy intake 900 kcal 975 kcal 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 Test meal 1500 kcal served Total energy intake 900 kcal 975 kcal 900 kcal 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.