Presentation on theme: "Uni S University of Surrey School of Biomedical and Molecular Sciences Protein and appetite Seminar Food & Drink Innovations Daventry, 22 June 2005 Professor."— Presentation transcript:
Uni S University of Surrey School of Biomedical and Molecular Sciences Protein and appetite Seminar Food & Drink Innovations Daventry, 22 June 2005 Professor Joe Millward Centre for Nutrition and Food Safety
High protein diets and weight loss Metabolic effects of protein Protein and appetite phenomenology -macronutrient hierarchy -fast and slow proteins -adaptation -clinical environment Protein and appetite regulation -mechanisms Implications and conclusions Protein and appetite
Skov et al Int J Obesity (1999) 23, 528±536 High carb 10.6MJ/d total energy intake High protein 8.9MJ/d total energy intake A high protein diet lowers energy intake and increases weight loss more than a high carb diet Weight loss on ad lib, low fat (30%) diets
Montignac diet (low GI high protein) Ad lib intake 8815kJ weight loss protein fat carbohydrate 195g 75g 164g AHA phase 1 diet (reduced fat) Ad lib intake 11695kJ weight stable carbohydrate fat protein 105g 93g 385g Dumesnil et al (2001) Effect of a low-glycaemic index–low-fat–high protein diet on the atherogenic metabolic risk profile of abdominally obese men BJNutr 86, 557–568 But see arguments about the paper in Nutrition Discussion Forum, B J Nutr (2002), 87, 211–214 Wolever: Low carbohydrate does not mean low glycaemic index! Tremblay Diet, satiety and obesity treatment response to Wolever A high protein, reduced carb diet lowers energy intake and induces weight loss compared with AHA (low fat) diet
High protein, very low carb diet (ATKINS), induces weight loss Is this due to a “metabolic advantage”? Weight loss4.7-11kg Diet trials data: Truby, Morgan, Millward et al BMJ in the press Alcohol 8% Baseline intake Carbs 37% Protein 16% Fat 39% Carbs 10% Protein 27% Fat 58% 2 month intake Alcohol 4%
Metabolic advantage of high protein diets through thermogenic changes Heat increment of feeding (about 20% energy intake for protein) not taken into account in calculations of true metabolisable energy (ME) intake e.g. change from 16% to 27% protein energy will increase overall thermic effect of food from 4.6 to 7.3% ME intake but Increased heat loss too small to have an effect (about 220kJ/d (50g week extra weight loss). i.e. “metabolic advantage” is trivial!
Alcohol 8% Weight loss4.7-11kg Dietary changes on the Atkins diet weight loss with high protein food through voluntary reduction in food intake Carbs 10% Protein 27% Fat 58% Baseline intake Carbs 37% Protein 16% Fat 39% 2 month intake Alcohol 4% Diet trials data: Truby, Morgan, Millward et al BMJ in the press energy intake 3MJ/d
Macronutrients and appetite control Protein is the most satiating macronutrient. Evidence from dietary intakes in free living subjects 1-3 Protein intake (% energy) correlated negatively with energy intake. CHO (% energy) did not correlate with total energy intake Fat (% energy) correlated positively with total energy intake. Meal test isoenergetic studies 5-10 satiating effect (joule for joule) of protein >carbohydrate Effect of food composition on following days energy intake 11 high protein intake suppression>isoenergetic amount of CHO. Each MJ of increased protein stores on day 1 reduced energy intake next day by 2.1 MJ Each MJ increased carbohydrate stores on day 1 reduced energy intake next day by 0.4 MJ Hierachy of satiation Protein>carbohydrate>fat energy from alcohol not regulated
References For Macronutrients and appetite control 1.DeCastro, J.M. (1987). Physiology and Behaviour 39, 561- 569. 2.DeCastro, J. & Elmore, D.K. (1988). Physiology and Behaviour 43, 159-165. 3.DeCastro, J.M. & Orozco, S. (1991). American Journal of Clinical Nutrition 52, 246-253. 4.Bingham, S.A., et al. British Journal of Nutrition 72, 619- 643. 5.Rolls et al Physiol Behav 1988; 43: 145 - 153. 6.Hill AJ, Blundell JE. Nutr Behav 1986; 3: 133 - 144. 7.Barkeling et al Int J Obes 1990; 14: 743 -751. 8.Stubbs et al Eur J Clin Nutr 1996; 50: 409 -417. 9.Teff KL, et al. Pharmacol Biochem Behav 1989; 34: 829 - 837. 10.Stubbs et al. Am J Clin Nutr 1995; 62: 330 - 337.
carbohydrate fat protein fat carbohydrate Ad lib energy intake during meal following previous (90 mins) meal of either 50g whey or casein protein Hall, Millward, Long, and Morgan Brit J Nutr: 2003 89 239-248 20% lower (p=<0·05) Protein and appetite- phenomenology 1. Proteins vary in their satiating effects: Fast (absorbing) > slow (absorbing) proteins
post-absorptive increases in plasma amino acids higher after whey cf. casein Protein preload Standard meal whey casein
2 nd Functional Food Centre Conference Sydney April 2005 www.nceff.com.au/conf2005/05-FrankDunshea.pdf Effect of dietary protein on satiety and metabolism in obese animal models Prof Frank Dunshea, Dept of Primary Industries, Victoria Mini-pigs & obese mice High protein diets reduced food intake and weight gain Whey protein isolate (30% GMP) > soy protein isolate (mini-pigs) > red meat, soy protein in mice Protein and appetite- phenomenology 1. Proteins vary in their satiating effects: other information
Protein and appetite- phenomenology 2. The satiating effect of protein on appetite is adaptive: -lower in people with high habitual protein intakes S.J. Long, A.R. Jeffcoat and D.J.Millward Effect of habitual dietary protein intake on appetite and satiety Appetite (2000) 35, 79-88 Subjects were divided into two groups on the basis of habitual protein intake: means of 10 g/kg/day (LP) and 14 g/kg/day (HP) and then a 13-day period of dietary manipulation increased differences in protein intake between groups to a mean of 0.75 g/kg/day (LP) and 1.96 g/kg/day (HP) and a satiety test was performed after three standardised meals during the day. Results support the hypothesis that the satiating effect of dietary protein varies inversely with habitual protein intake. LP HP (h) meal
Protein and appetite in the clinical environment: Protein depletion and repletion appears to regulate appetite during catch-up growth Days Body weight (kg) 020406080100120140160180200220240260280 4 6 8 10 12 14 expected weight-for height normal growth catch-up Wasting Catch-up growth (nutritional rehab) Increased Hunger stimulated: low satiating effect of dietary protein appetite Normal satiety stimulated: High satiating effect of dietary protein Millward D.J. 1995 A protein-stat mechanism for the regulation of growth and maintenance of the lean-body mass. Nutrition Research Reviews 8; 93-120.
Nutrient-related post-absorptive regulatory mechanisms of appetite control
Protein-related mechanisms of satiety protein Pre absorptive signals Low palatability (some proteins), but Umami (5 th taste) is important positive taste stimulus gut hormones Increased metabolic rate Increased gluconeogenesis prevents hypoglycemia CNS chemosensor system -for essential amino acids in the anterior piriform cortex -in response to histidine, tryptophan and tyrosine as precursors of histamine, serotonin and catecholamines (dopamine, adrenaline, noadrenaline) Toxicity at high levels:- individual amino acids, metabolites and ammonia post-absorptive signals amino acids
Journal of Endocrinology (2005) 184, 291–318, http://www.endocrinology-journals.org Peripheral peptide/protein hormone signals which might be invoved in protein-related mechanisms of satiety. + + - - - - - -?-? - Appetite effects
These results implicate post-absorptive increases in plasma amino acids together with both CCK and GLP-1 as potential mediators of the increased satiety response to whey and emphasise the importance of considering the impact of protein type on the appetite response to a mixed meal. Protein and appetite “Fast” and “slow” proteins
post-absorptive increases in GLP-1 higher after whey cf. casein Protein preload Standard meal whey casein
post-absorptive increases in CCK higher after whey cf. casein Protein preload Standard meal whey casein
GMP (glyco-macropeptide or CDP (casein-derived peptide) or CGP (casein glycopeptide ) GMP, or glycomacropeptide: phenylalanine-free milk derived proteins. -derived from casein in cheesmaking, -can comprise up to 20% of whey protein. -Used to treat PKU (phenylketonuria) -promotes growth of bifidobacteria -has immunomodulatory and bacterial toxin binding effects has appetite-suppressing properties -increases CCK -efficacy dependent on glycosylation, non-glycosylated GMP has no effect - presence of terminal sialic acid also important for CCK effect - polymorphic forms have variant effects on CCK production. Yvon M et al Effects of caseinomacropeptide (CMP) on digestion regulation. 1994. Reprod Nutr Dev, 34, no. 6:527-37
Journal of Endocrinology (2005) 184, 291–318, http://www.endocrinology-journals.org Amino acids + + - - - - - -?-? - ? Peripheral peptide/protein hormone signals which might be involved in protein-related mechanisms of satiety.
High protein diets enable better weight loss whether they are low fat high carbs or high fat low carbs High protein diets reduce food intake by increasing satiety Proteins vary in their satiating effects: Fast (absorbing): e.g whey > slow (absorbing) e.g. casein/soya The satiating effect of protein on appetite is adaptive and a) high in adults compared with during rapid growth b) lower in people with high habitual protein intakes We are only starting to get an insight into the mechanisms Protein and appetite Implications and conclusions
Opportunities to use high protein foods as a means to manage appetite and obesity Fast proteins best for satiating applications? whey, especially GMP (already in the market place) other “fast” highly digestible proteins (meat, egg, fish??) Slow proteins best in clinical feeds (low satiation) casein, soya/legumes (lower digestibility???) Low GI- high protein combinations Protein and appetite Implications for functional foods
Uni S University of Surrey School of Biomedical and Molecular Sciences Thank you for your attention! Professor Joe Millward Centre for Nutrition and Food Safety firstname.lastname@example.org