dietary strategies to promote satiety.pptx

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1. Dietary Strategies to Promote Satiety

2. Introduction Overweight and obese individuals are susceptible to several medical conditions that contribute to morbidity and mortality including diabetes and cardiovascular disease. According to the National Nutrition Survey 2018, obesity is a public health issue of concern in Pakistan, with 7.7% of adolescent boys and 5.5% of adolescent girls affected. Overweight and obesity affect adolescents similarly in both rural and urban areas of Pakistan.

3. Introduction Obesity has reduced longevity in several industrialized countries; however, the effects are more severe in the United States, which may be due to the unusually high rate of obesity in younger age groups and higher rates of severe obesity. Obesity is a multifaceted problem with contributing factors that are undoubtedly complex and include genetics, endocrine function, behavioral patterns, and their environmental determinants

4. Introduction Obesity management relies on lifestyle changes, medications, or surgery, with lifestyle modification aiming for a negative energy balance through increased activity and reduced calorie intake. However, studies indicate exercise alone isn't highly effective for weight loss. Consequently, dietary changes play a crucial role, but their success varies, often leaving a significant number of individuals as non-responders. Acknowledging this limitation is essential for developing more practical and effective weight management strategies.

5. Introduction Success of a weight-loss dietary regimen is closely related to compliance, which, in turn, is largely dependent on hunger, appetite, and satiety. As indicated by extensive research in the psychology, physiology, behavior, endocrinology, and pharmacology of hunger, appetite, and satiety, the significance of these factors is well recognized.

6. Appetite and Satiety Appetite is a complex interplay of biological and environmental factors in the psychobiological system, involving psychological events, peripheral physiology, and the central nervous system. Apart from satisfying appetite sensations, various factors like sensory hedonics, social pressure, and boredom contribute to eating episodes.

7. Appetite and Satiety Satiety, inhibiting further eating, involves processes like satiation, and both act together to determine eating behavior. The satiety cascade, examining sensory, cognitive, post- ingestive , and post-absorptive processes, offers a framework.

8. Appetite and Satiety Eating behavior is controlled by metabolic factors that drive appetite and satiety and sensory factors that influence food choice. In the brain, the sensory signals of food are associated with the metabolic consequences leading to the conditioning of eating and nutrition patterns. Cognitive factors such as an estimation of the satiating effect of foods and the timing of the next meal contribute to making eating a learned behavior.

9. Appetite and Satiety Short-term control of eating is influenced by episodic signals that arise mainly from the gastrointestinal (GI) tract and are generated at regular intervals as food intake occurs. The peptides involved in GI signaling include cholecystokinin, glucagon-like peptide-1(GLP-1), peptide YY (PYY), and ghrelin. Long-term control of eating, also referred to as tonic signaling, reflects the metabolic state of adipose tissue.

10. Appetite and Satiety The composition of macronutrients, energy density, and physical structure play a role in influencing satiety. Amino acids, fatty acids, and carbohydrates exhibit diverse effects on markers of appetite regulation, with each nutrient interacting uniquely with the processes that mediate satiety. Dietary protein, for example, may contribute to weight loss by increasing energy expenditure and promoting a sense of fullness.

11. Appetite and Satiety Carbohydrates that evade digestion, or which Dietary Strategies and Satiety have a pronounced effect on glucose metabolism, have the potential to produce changes in appetite and affect satiety. Similarly, novel oils designed to prolong their presence in the GI tract can potentially produce beneficial effects on appetite and satiety.

12. Dietary Protein and the Regulation of Food Intake and Body Weight

13. Protein is a highly satiating macronutrient, with research spanning 40 years indicating its potential in regulating body weight. High-protein diets may reduce the risk of positive energy balance and weight gain, promoting weight loss by increasing energy expenditure and inducing a feeling of fullness. Short-term studies show that high-protein diets lead to greater satiety compared to isoenergetic intakes of carbohydrates and fats. Protein affects energy expenditure through diet-induced thermogenesis, involving the utilization of adenosine triphosphate and the body's inability to store excess protein. This increased metabolic activity contributes to higher resting metabolic rates.

14. Studies suggest that protein-induced satiety may be linked to an increase in anorexigenic hormones (GLP-1 and PYY) and a decrease in the orexigenic (appetite-stimulating) hormone ghrelin. Specific amino acids in protein may influence satiety by acting as precursors for neurotransmitters involved in appetite regulation. (tryptophan precursor for the serotonin, tyrosine converted into dopamine and nor-epinephrine, and histidine converts into histamine). However, there are health risks associated with high-protein diets, such as hypercalciuria and potential renal issues. While high-protein diets have shown effectiveness in weight loss, further research is needed to determine their long-term safety and efficacy for weight maintenance.

15. Milk and Milk products Dairy products, particularly milk, have been linked to increased satiety and a reduction in overall food intake. The protein and calcium components in dairy are believed to play a role in regulating food intake and preventing weight gain. Milk contains two main types of proteins, casein, and whey, in different proportions. (Casein and whey protein comprise 80% and 20%, respectively, of cow, sheep, goat, and buffalo milk.)

16. Milk and Milk products Whey protein is quickly absorbed, leading to a rapid but short-lived increase in amino acids, while casein is absorbed more slowly, resulting in a prolonged release of amino acids. Both proteins contribute to satiety after consuming dairy products. Milk proteins contain bioactive peptides, including opioid peptides, which can affect gastrointestinal functions. Opioid peptides, derived from casein, may delay gastric emptying and influence eating behavior.

17. Milk and Milk products Whey proteins, especially rich in branched-chain amino acids like leucine, can suppress overall food intake by affecting certain genes in the brain. Milk proteins stimulate the release of hormones involved in appetite regulation, such as insulin and peptides like cholecystokinin, GLP-1, and PYY. Calcium in dairy products may have a role in energy metabolism and obesity control. Some evidence suggests that calcium deficiency may lead to increased intake of fatty and sugary foods.

18. Milk and Milk products Epidemiological evidence suggests a potential association between reduced adiposity and the consumption of yogurt or milk, but cheese may have the opposite effect. Results on the relationship between dairy consumption and weight status in prospective studies are inconsistent. Studies on the effects of dairy consumption on body weight in controlled trials show mixed results. High dairy intake may aid weight loss in energy-restricted diets, and dairy components other than calcium may contribute to these effects. In conclusion, dairy products, through their protein, calcium, and other bioactive components, may influence satiety, hormonal responses, and body weight, but the effects can be influenced by various factors.

19. Meat, Fish and Eggs Dietary proteins are essential for various bodily functions, providing amino acids that are crucial for metabolic processes. Protein quality, determined by factors such as amino acid composition, is vital for its physiological effects. Amino acids like histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine are essential and found in complete proteins like meat, poultry, fish, eggs, and dairy. The body's post-meal protein synthesis is influenced by the amino acid composition of dietary protein. Complete proteins, containing all essential amino acids, contribute to a higher thermogenic response.

20. Meat, Fish and Eggs While protein-induced satiety has been demonstrated in several studies, there is less evidence for the role of protein from different sources on the regulation of appetite and food intake. Consumption of pork, beef, or chicken meals matched for energy and macronutrient content did not differ in their effects on satiety, food intake, or appetite hormones (cholecystokinin, PYY, ghrelin, and insulin). Among protein-rich foods, fish was found to be the most satiating item, followed by beef, baked beans, eggs, cheese, and lentils in a study to assess the satiating capacity of several foods. Studies have explored the relationship between meat consumption and weight, with varying results. Some studies suggest associations between red meat, poultry, and processed meat intake and weight gain. However, the evidence is primarily based on observational studies, and controlled trials are needed for a more conclusive understanding of how protein sources impact appetite, satiety, food intake, and body weight.

21. Legumes Legumes , such as alfalfa, clover, green beans, peas, peanuts, soybeans, dry beans, broad beans, dry peas, chickpeas, and lentils, are a good source of protein and fiber. Pulses , which are a type of legume harvested for the dry grain, include dry beans, chickpeas, lentils, and peas. Pulses are high in fiber, which helps reduce the energy density of food and lowers the glycemic response. In a study, different legumes like chickpeas, lentils, navy beans, and yellow peas were compared to white bread. The study found no significant difference in appetite, satiety, or food intake. However, homemade beans increased satiety compared to glucose, while canned beans reduced food intake at a later pizza meal compared to glucose. Replacing wheat flour with chickpea flour in bread or including legumes in pasta and tomato sauce did not significantly affect satiety or energy intake. Lentils, in particular, led to lower food intake compared to chickpeas and pasta with sauce in one study.

22. Legumes Isoenergetic preloads of lentils and yellow peas increased satiety and reduced food intake compared to a "macaroni and cheese" meal. Chickpea supplementation in the diet increased satiety, possibly due to the higher fiber intake. Soy protein is considered a complete protein, and studies suggest it may have satiety-enhancing effects. However, more research is needed to establish a clear link between soy protein consumption and reduced food intake. High consumption of pulses has been inversely associated with body weight. Several studies have explored the effectiveness of incorporating pulses in energy-restricted diets, showing varying results. While some studies suggest a beneficial effect on weight loss, there is not enough evidence to strongly support the role of legumes in weight management.

23. Nuts Nuts are fruits with a hard ovary wall containing one seed. Common edible nuts include almonds, hazelnuts, walnuts, pistachios, pine nuts, cashews, pecans, macadamia, and Brazil nuts. Peanuts, although botanically legumes, are often included in the nuts food group. Nuts are nutrient-dense, rich in unsaturated fats, and high in energy but have not been associated with weight gain in various studies. The impact of nuts on body weight involves increased satiety, higher energy expenditure, and incomplete digestion, leading to increased fecal fat. Nuts are energy-dense, high in fiber and protein, which contribute to feelings of satiety. The effort required for chewing nuts and the act of shelling them may also influence satiety.

24. Nuts Studies suggest that nut consumption may lead to a spontaneous reduction in energy intake from other sources, resulting in an overall reduction in energy intake. Nuts may increase resting energy expenditure (REE), although findings are inconsistent. Incomplete digestion of nuts may limit fatty acid availability, and their cell walls, resistant to degradation, can increase fecal fat excretion. Epidemiological studies, like the Seguimiento Universidad de Navarra study, indicate that frequent nut consumption is associated with a reduced risk of weight gain. Intervention trials on almonds, peanuts, pistachios, and walnuts show varying effects on weight, with some studies suggesting potential benefits for weight loss. In summary, nuts, despite being energy-dense, do not appear to contribute to weight gain. Increased satiety, reduced energy intake from other sources, and incomplete digestion leading to increased fecal fat excretion are proposed mechanisms for this phenomenon. The inclusion of nuts in energy-restricted diets may help with adherence, facilitate weight loss, and improve body composition. However, further research is needed to confirm these effects on diet-induced thermogenesis and REE.

25. CARBOHYDRATES AND THE REGULATION OF FOOD INTAKE AND BODY WEIGHT

26. Carbohydrates influence satiety and food intake through several mechanisms related to their hormonal effects, intrinsic properties, and intestinal fermentation. The hormonal effects of carbohydrates on satiety are mediated by insulin and GI hormones whereas the intrinsic properties relate to the bulking and viscosity effects of dietary fiber. Carbohydrates that elude small intestinal digestion enter the large bowel and are fermented by colonic microorganisms into short-chain fatty acids which have been shown to enhance satiety. The manipulation of the carbohydrate content of the diet has been explored as a means of regulating body weight

27. Glycemic Index and Glycemic Load The Glycemic Index (GI) is a measure that classifies carbohydrates in foods based on their impact on blood sugar levels after consumption. It is defined as the incremental area under the curve (AUC) for the blood glucose response to a 50g carbohydrate portion of a test food, expressed as a percentage of the response to an equivalent amount of carbohydrate from a reference food (usually glucose or white bread). Foods are categorized as low GI (<55) or high GI (>70). The Glycemic Load (GL) considers both the GI and the amount of carbohydrates consumed. It is the product of the GI and the available carbohydrate in the portion of food. The GL directly measures the impact on blood glucose levels.

28. Glycemic Index and Glycemic Load Low-GI foods, which cause a slower rise in blood sugar, have been associated with increased short-term satiety. However, the evidence for the long-term impact on body weight is inconsistent. Some studies suggest that low-GI diets may lead to weight loss, while others do not show a significant difference. The association between GI or GL and obesity is debated. Some studies indicate that increasing the GI of a diet is linked to higher BMI, but a collective analysis doesn't strongly support this. Meta-analyses have shown modest weight loss with low-GI diets, especially when food intake is ad libitum (unrestricted).

29. Glycemic Index and Glycemic Load The concept of low-GI diets focuses on choosing foods that have a lower impact on blood sugar levels, typically including nonstarchy vegetables, fruits, legumes, and minimally processed grains. These diets may be beneficial for conditions like diabetes and can contribute to overall health. However, the practicality and consistent impact on long-term weight management are still debated.

30. Dietary Fiber Dietary fiber is a type of carbohydrate found in plants that has several health benefits. It is classified into soluble and insoluble fiber based on its water solubility. Soluble fiber ferments in the colon, while insoluble fiber adds bulk to stool. The effects of dietary fiber on appetite and satiety (feeling full) involve various mechanisms. Fiber can slow down the passage of nutrients through the digestive tract, releasing hormones that regulate appetite. It also lowers the energy density of food, making you feel full of fewer calories. The act of chewing high-fiber foods takes time and effort, contributing to satiety. Additionally, highly viscous soluble fiber delays stomach emptying, increasing feelings of fullness.

31. Dietary Fiber The influence of dietary fiber on body weight is linked to its impact on satiety, food intake, and metabolizable energy (energy absorbed by the body). Epidemiological data suggests that increased fiber intake is associated with lower weight gain over time. Studies indicate that higher fiber intake, especially from fruits and cereals, is linked to reduced weight gain and waist circumference. Research also shows that fiber consumption, regardless of the type, can reduce appetite and energy intake. Over time, regular fiber intake is associated with a modest decrease in body weight. However, the effects of fiber from fruits and vegetables on body weight are inconsistent in the research.

32. Dietary Fiber In simple terms, including fiber-rich foods in your diet, such as whole grains, fruits, and vegetables, can help you feel full, reduce overall calorie intake, and may contribute to maintaining a healthy weight.

33. Bread and Cereals Cereals encompass a variety of grains like wheat, rice, barley, corn, and oats. Whole-grain products, recommended for their health benefits, should contain the endosperm, germ, and bran components in the same proportion as naturally found in the seed. Despite recommendations for increased whole-grain intake, many people fall short. Whole grains, particularly those found in breakfast cereals and breads, can influence satiety and impact body weight. The 2010 Dietary Guidelines for Americans recommend at least three servings of whole grains daily. However, while total grain servings in the U.S. are often high, whole-grain consumption remains insufficient.

34. Bread and Cereals Rye, rich in soluble and insoluble fiber, has demonstrated satiating effects. The type and amount of fiber, as well as the specific grain variety, influence these outcomes. Oats and barley, containing beta-glucan, a soluble fiber, have shown mixed results regarding their impact on satiety. Lupin-kernel flour, rich in protein and fiber, has demonstrated potential for increasing satiety. Observational studies suggest that whole-grain bread may have positive effects on weight status, while randomized controlled trials (RCTs) exploring the impact of specific grains on satiety and weight are limited. Breakfast cereals, especially those high in fiber, have shown promise in influencing satiety and reducing subsequent energy intake.

35. Bread and Cereals In summary, incorporating whole grains, including cereals, into the diet can contribute to feelings of fullness and potentially aid in weight management. However, the effects vary based on the type and amount of fiber, the specific grain, and the individual's overall diet.

36. Fruits and Vegetables The energy density of food depends on its water content, and fat is the most calorie-dense nutrient. Fruits and vegetables, with high water content and low fat, are low in energy density. Consuming them is linked to increased feelings of fullness and positive effects on weight management. Studies show that adding vegetables like spinach or carrots to meals in portions of 200 grams or more can increase feelings of fullness. Beans and salads have also been found to influence satiety. Fruits, such as apples and oranges, in their whole form, tend to be more satisfying than their juice or pureed counterparts.

37. Fruits and Vegetables While observational studies suggest an association between increased fruit and vegetable consumption and better weight outcomes, not all research agrees. Some studies find weak or no direct link between fruit and vegetable intake and changes in body weight. Therefore, while fruits and vegetables are nutritious and can contribute to a healthy diet, their impact on weight may be influenced by various factors, including individual eating behaviors.

38. Fats and the Regulation of Food Intake

39. The regulation of fat intake involves a complex interplay of physiological events. It begins with the perception of fat through the nose or mouth, where volatile flavor molecules are detected. The texture of food, experienced during chewing and swallowing, also plays a role in fat perception. Evidence suggests that the sensing of fat may involve chemoreception. There are various mechanisms proposed for the detection of fatty acids (FAs), including the inhibition of potassium channels. Long-chain cis-polyunsaturated FAs have been shown to affect taste receptor cells. The taste detection threshold depends on the length of the FA chain. Lipases, enzymes present in digestive juices, aid in the chemosensory process. The ability to taste certain fats may be an evolutionary adaptation to avoid ingesting harmful compounds.

40. Fats stimulate receptor cells that send signals to brain areas involved in processing emotions and memories. This overlap in neuroanatomical structures explains the emotional responses to the odor of fats. Fats, being higher in energy density than carbohydrates and proteins, contribute to the palatability of foods. Palatability can influence food intake, with highly palatable and energy-dense foods often leading to overconsumption. While fats stimulate intake due to their palatability, they may not induce satiety. The combination of taste and smell sensations, such as those from vanilla, can enhance satiety following a high-fat meal. However, the role of palatability in fat-induced overeating is not entirely clear. Fats in the gastrointestinal (GI) tract can elicit satiety signals, affecting the release of hormones like cholecystokinin.

41. Bariatric surgery, specifically Roux-en-Y gastric bypass, has been effective in inducing weight loss. It results in the rapid delivery of partially digested nutrients to the distal GI tract, activating the ileal brake and promoting satiety. The physicochemical properties of fats, such as chain length, degree of saturation, and form (e.g., medium chain triglycerides), influence their effects on GI function and satiety. However, the role of the degree of saturation in modulating fat effects on the GI tract is not fully understood.

42. Manipulating the digestion of fats, such as by using galactolipids or emulsions like Olibra ™, can affect satiety. However, the efficacy of these strategies in promoting weight loss and reducing food intake is still debated. In summary, the regulation of fat intake involves a combination of sensory perception, neural responses, and hormonal signals. Palatability, GI effects, and the interplay of various factors contribute to the complex relationship between fat consumption and satiety.

43. Teas, Caffeine, and Pungent Foods

44. Some food components, like those found in tea, don't provide energy but can increase energy expenditure. In tea, polyphenols such as epigallocatechin gallate (EGCG) and caffeine play a role. These compounds inhibit enzymes that degrade norepinephrine and c-AMP, leading to increased heat production and energy expenditure. A meta-analysis suggests that green tea with EGCG and caffeine can aid weight loss and maintenance, with greater sensitivity in low-caffeine consumers and variation across ethnicities. Caffeine, found in coffee, tea, cocoa, chocolate, and cola drinks, has demonstrated short-term effects on energy expenditure. However, long-term studies on its impact on body weight are inconclusive. Some evidence supports the role of green tea in weight loss, but the clinical significance may be limited. Capsaicin, the pungent component in red hot peppers, increases thermogenesis by stimulating catecholamine release. It activates receptors in neurons on the tongue, leading to increased energy expenditure. Studies show that red pepper-containing meals can reduce appetite and fat intake, especially in high-fat diets. However, long-term studies on capsaicin's impact on weight maintenance are limited.

45. Capsinoids , nonpungent substances related to capsaicin, found in sweet peppers, have been investigated for their thermogenic effects. Capsinoid supplementation for 12 weeks didn't affect energy expenditure or body weight but increased fat oxidation and reduced abdominal fat. In summary, tea components, caffeine, capsaicin, and capsinoids can influence energy expenditure and, to some extent, satiety and food intake. While short-term effects are evident, long-term impacts on body weight are less clear, and compliance with diets containing these components may be challenging.

46. Energy Density

47. Energy density is defined as the amount of energy per unit weight of a food or beverage (most commonly expressed as kilocalories per gram or kilojoules per gram). The amount of water present in food is a major influencer of energy density because water adds weight without adding calories. Macronutrient composition also influences the energy density of a food with fat providing 9 kcal/g compared to 4 kcal/g for carbohydrates and protein. Dietary fiber adds weight while contributing minimal energy. Thus, food that is high in water and/or fiber is often low in energy density.

48. Substituting pureed vegetables into recipes has been effective in lowering energy density and decreasing daily energy intake. Short-term studies strongly support the idea that lower energy-density meals can reduce calorie intake. Long-term studies on energy density's role in weight loss yield mixed results. Some trials adding snacks of varying energy density show weight loss, while others focusing on counseling report varied outcomes. Though lowering energy density may aid weight loss, there's no evidence it's superior to other strategies. While choosing foods with lower energy density can be a helpful tool for weight loss, exceptions exist. Sugar-sweetened beverages, despite having low energy density, are linked to excess calorie intake and weight gain. Nuts, though high in energy density, don't seem to cause weight gain when consumed regularly.