The macronutrient protein has garnered fame for its ability to increase satiety so consumers no longer desire to eat. A 2008 Maastricht University review reported meals with p 25 to 81 percent of energy from protein increase satiety and reduce subsequent food intake.¹ They said protein-induced satiety has been shown with high-protein diets, lasting up to six months. And a review from the University of Texas, Galveston, from that same year noted protein ingestion increased satiety to a greater extent than carbohydrate or fat, reduced calorie consumption under ad libitum dietary conditions, increases thermogenesis and provides a stimulatory effect on muscle protein anabolism, favoring the retention of lean muscle mass while improving metabolic profile.²

All types of protein can have the weight-management effect. Glanbia's Prolibra capitalizes on dairy protein. The company's research and development center evaluated Prolibra, which is a specialized whey fraction high in leucine, bioactive peptides and milk calcium, in a randomized, double blind, parallel-arm, 12-week study.  Researchers found Prolibra  caused subjects who were on a 500-calorie/d diet to lose significantly more body fat and preserve more lean muscle compared to subjects consuming the diet without the supplement.³

Potato protein contains the active component proteinase inhibitor II (PI2) that helps suppress appetite by releasing cholecystokinin (CCK), a peptide hormone that stimulates digestion of fat and protein. The body uses CCK to signal the brain that food has been eaten, which helps to create feelings of fullness and satisfaction.

Both Kemin and Cyvex offer potato protein ingredients. Kemin's Sendesta®, an all-natural potato protein, has been shown to increase satiety in unpublished human clinical trials. Kemin reported the ingredient has been tested in more than 400 participants and has shown benefits for satiety, CCK release and healthy weight loss. Cyvex is currently working on a clinical study of its potato protein ingredient Solathin.

Published studies show how CCK and potatoes reduce appetite. CCK may decrease food intake because of its effects on gastrointestinal (GI) motility, according to a 1989 paper from Thomas Jefferson University, Philadelphia. The paper said CCK is one of several satiety signals that can cause a profound decrease in food intake when administered in pharmacologic doses.⁴

A 2011 study from Japan noted a potato extract that contains 60-percent carbohydrate and 20-percent protein suppressed food intake in rats through the CCK secretion induced by direct stimulation on enteroendocrine cells and through inhibition of the inhibitory protein trypsin.23 And another 2011 study from Rutgers University, New Brunswick, NJ, found a novel protease inhibitor concentrate derived from potato reduced food intake and body weight gain in healthy rats when administered orally by increasing circulating CCK levels through a trypsin-dependent mechanism.⁵

The botanical Caralluma fimbriata is widely consumed in India, and can also help control hunger and reduce abdominal adiposity. Gencor offers Slimaluma, a GRAS C. fimbriata ingredient marketed for increasing satiety, helping to maintain body weight, and thus helping heart health and reducing the risks associated with metabolic syndrome.

Research from Bharathidasan University, Tiruchirappalli, India, backs up these claims as a 2012 study said C. fimbriata extract suppressed appetite, and provided antiobesogenic and metabolic benefits.⁶ In the study, C. fimbriata extract induced significant and dose-dependent inhibition of food intake in rats, with dose-related prevention of gains in body weight, liver weight and fat mass. Alterations in serum lipid profiles associated with weight gain were similarly inhibited, as were the typical increases in serum leptin levels.

In several unpublished studies on Simaluma, the C. fimbriata extract prevented rats from becoming obese, reduced leptin levels by 4.1 percent in rats compared to a rise of 293 percent in controls, and reduced the growth of fat cells by 35 percent in cell lines. And in a published study from 2011, Slimaluma inhibited pre-adipocyte cell division, suggesting it has the potential to inhibit obesity.⁷

Other botanicals have shown to affect weight management. For instance, Meratrim (from InterHealth Nutraceuticals), a proprietary plant extract blend of Sphaeranthus indicus and Garcinia mangostana, two herbs traditionally used in Southeast Asia, has been shown in two studies to reduce body weight, BMI and waist circumference within two weeks.

After eight weeks of 400 mg/d Meratrim supplementation, obese men and women experienced reductions in body weight by 11.32 pounds (3.8-times better than placebo), BMI, waist circumference by 4.66 inches (1.8-times better than placebo), hip circumference by 2.57 inches (1.8-times better than placebo), blood cholesterol, triglycerides, glucose and the low-density lipoprotein (LDL)/high-density lipoprotein (HDL) ratio.⁸ The reductions in serum cholesterol and triglycerides were statistically significant in Meratrim-supplemented subjects compared to placebo.

An unpublished study combined data from the previous Meratrim study (n=56) with a second study of 40 subjects who also took 400 mg tid of Meratrim or placebo (30 min before breakfast and dinner) for eight weeks. The combined data showed Meratrim significantly reduced body weight by 11.5 pounds (3.5-fold better than placebo), body weight by 4.5 lbs (2.7-fold better than placebo), waist circumference by 4.7 inches and hip circumference by 2.5 inches. Meratrim also significantly increased adiponectin levels, suggesting an enhanced fat metabolism, and improved serum lipid profile and blood glucose levels.

Fiber also is  known to increase satiety. It consists of a number of different carbohydrates that resist digestion and absorption in the small intestine, but may be partially or completely fermented in the human large intestine by bacteria. Dietary fiber and whole grains contain a unique blend of bioactive components including resistant starches, vitamins, minerals, phytochemicals and antioxidants. Taking fiber supplements has shown to be effective as complementary or alternative agents in the management metabolic syndrome complications, including obesity, according to a 2010 review.⁹ However, the authors noted fibers ability to modify gastric sensors (and thus affect metabolism) depends greatly on fiber type.

Another review from 2010 noted epidemiological and clinical studies demonstrated intake of dietary fiber and whole grains is inversely related to obesity, type-2 diabetes, cancer and cardiovascular disease (CVD).¹⁰ The Kansas State University, Manhattan, researchers speculated the different components of fiber, including arabinoxylan, inulin, pectin, bran, cellulose, beta-glucan and resistant starch may decrease the risk for certain diseases because they change intestinal viscosity, nutrient absorption, rate of passage, production of short chain fatty acids (SCFAs) and production of gut hormones.

Pectin, one of the fiber components called out by the Kansas researchers, increased satiety, delayed gastric emptying in obese patients and may be a useful adjuvant in the treatment of disorders of overeating, according to a study from 1988.¹¹ Researchers studied gastric emptying of solids in nine adult obese subjects on two separate days in a randomized trial. On the first day, 15 g of pectin was added to the meal, and on second day, 15 g of methylcellulose was added to serve as control. Pectin significantly delayed gastric emptying time by 45 minutes, and it also significantly increased subjects' sensation of satiety. And a German study from 1982 reported a diet with 3 g/d of added apple pectin led to a weight loss of 5.9 kg on average, and a decreased cholesterol levels.¹²

Keeping the diet low on the glycemic scale can also help increase feelings of fullness, as blood glucose is an important satiety signal. Glycemic index (GI) is a measure of blood glucose excursion per unit of carbohydrate. Foods with a high GI are rapidly digested, absorbed and transformed into glucose, causing accelerated surges in blood glucose and insulin, earlier return of hunger sensation and a potential for excessive caloric intake. Conversely, low-GI foods decrease blood glucose and insulin excursion, promoting greater fat oxidation and increasing satiety. Modern food-processing technology has produced many food products with high glycemic loads. Simple sugars and refined carbohydrates are high on the GI, and research has shown reducing them, as well as increasing fat and fiber content, can slow the influx of glucose into the blood, improve satiety signals and promote better weight management.¹³

A 2011 meta analysis from Hong Kong said epidemiological and clinical trials suggest a role for a low-GI diet in the management of childhood obesity and associated cardiometabolic risks, although researchers noted results are not always consistent.¹⁴ In adults, a 2012 study from the University of Washington, Seattle, reported reducing glycemic load and/or increasing fiber lowered calories consumed, improved energy balance and reduced cancer risk.¹⁵ Participants reported 7-pecent greater satiation and fewer food cravings on a low GI diet than those on a high GI diet.

References listed on the next page.

References:

1.       Veldhorst M et al. "Protein-induced satiety: effects and mechanisms of different proteins." Physiol Behav. 2008 May 23;94(2):300-7.

2.       Paddon-Jones D et al. " Protein, weight management, and satiety." Am J Clin Nutr. 2008 May;87(5):1558S-1561S.

3.       Frestedt JL et al. A whey-protein supplement increases fat loss and spares lean muscle in obese subjects: a randomized human clinical study." Nutr Metab (Lond). 2008 Mar 27;5:8

4.       Peikin SR. Role of cholecystokinin in the control of food intake." Gastroenterol Clin North Am. 1989 Dec;18(4):757-75.

5.       Nakajima S et al. " Potato extract (Potein) suppresses food intake in rats through inhibition of luminal trypsin activity and direct stimulation of cholecystokinin secretion from enteroendocrine cells." J Agric Food Chem. 2011 Sep 14;59(17):9491-6.

6.       Komarnytsky S, Cook A, Raskin I " Potato protease inhibitors inhibit food intake and increase circulating cholecystokinin levels by a trypsin-dependent mechanism." Int J Obes (Lond). 2011 Feb;35(2):236-43.

7.       Kamalakkannan S et al Antiobesogenic and Antiatherosclerotic Properties of Caralluma fimbriata Extract." J Nutr Metab. 2010;2010:285301.

8.       Kamalakkannan,S. et al. Effect of Caralluma Fimbriata Extract on 3T3-L1 Pre-Adipocyte Cell Division" Food & Nut Sci 2011, DOI:/fns.2011

9.       Bagchi, D  et al. "Efficacy and Tolerability of Merastin - a Novel Herbal Formulation for Weight Management: A Randomized Double Blind Placebo Controlled Clinical Study." The FASEB Journal. 2011;25:601.9

10.   Papathanasopoulos A, Camilleri M. Dietary fiber supplements: effects in obesity and metabolic syndrome and relationship to gastrointestinal functions." Gastroenterology. 2010 Jan;138(1):65-72.e1-2.

11.   Lattimer JM, Haub MD. Effects of dietary fiber and its components on metabolic health." Nutrients. 2010 Dec;2(12):1266-89

12.   Di Lorenzo C. et al. Pectin delays gastric emptying and increases satiety in obese subjects." Gastroenterology. 1988 Nov;95(5):1211-5.

13.   Matzkies F, Budelski I, Webs B. [Effect of a fiber-containing dietary formula on metabolism]." [Article in German] Fortschr Med. 1982 May 20;100(19):917-20.

14.   Kong AP et al. Role of low-glycemic index diet in management of childhood obesity." Obes Rev. 2011 Jul;12(7):492-8. DOI: 10.1111/j.1467-789X.2010.00768.x.

15.   Chang KT et al. Low glycemic load experimental diet more satiating than high glycemic load diet." Nutr Cancer. 2012 Jul;64(5):666-73.