Natural Inhibitors of Pancreatic Lipase as New Players in Obesity Treatment.
Abstract: Obesity is a multifactorial disease characterized by an excessive weight for height due to an enlarged fat deposition such as adipose tissue; which is attributed to a higher calorie intake than the energy expenditure. The key strategy to combat obesity is to prevent chronic positive impairments in the energy equation. However; it is often difficult to maintain energy balance; because many available foods are high-energy yielding; which is usually accompanied by low levels of physical activity. The pharmaceutical industry has invested many efforts in producing antiobesity drugs; but only a lipid digestion inhibitor obtained from an actinobacterium is currently approved and authorized in Europe for obesity treatment. This compound inhibits the activity of pancreatic lipase; which is one of the enzymes involved in fat digestion. In a similar way; hundreds of extracts are currently being isolated from plants; fungi; algae; or bacteria and screened for their potential inhibition of pancreatic lipase activity. Among them; extracts isolated from common foodstuffs such as tea; soybean; ginseng; yerba mate; peanut; apple; or grapevine have been reported. Some of them are polyphenols and saponins with an inhibitory effect on pancreatic lipase activity; which could be applied in the management of the obesity epidemic.
Nut consumption; weight gain and obesity: Epidemiological evidence
BACKGROUND AND AIMS: Short-term trials support that adding tree nuts or peanuts to usual diets does not induce weight gain. We reviewed the available epidemiological evidence on long-term nut consumption and body weight changes. We also report new results from the SUN ("Seguimiento Universidad de Navarra") cohort. METHODS AND RESULTS: Published epidemiologic studies with =1-yr follow-up were located. Two published reports from large cohorts (SUN and Nurses Health Study-2) showed inverse associations between frequency of nut consumption and long-term weight changes. A beneficial effect of a Mediterranean diet supplemented with tree nuts on waist circumference was reported after 1-yr follow-up in the first 1224 high-risk participants in the PREDIMED ("PREvencion DIeta MEDiterranea") trial. After assessing 11;895 participants of the SUN cohort; a borderline significant (p value for trend = 0.09) inverse association between baseline nut consumption and average yearly weight gain (multivariate-adjusted means = 0.32 kg/yr (95% confidence interval: 0.22-0.42) and 0.24 (0.11-0.37) kg/yr for participants with no consumption and >4 servings/week; respectively) was found after a 6-yr follow-up. CONCLUSIONS: Consumption of nuts was not associated with a higher risk of weight gain in long-term epidemiologic studies and clinical trials.
Nuts and health outcomes: new epidemiologic evidence.
This article reviews recent epidemiologic evidence on nut intake and health outcomes. It focuses on studies in which nut consumption is directly assessed or when nuts are included in a dietary score or pattern. Epidemiologic studies have been remarkably consistent in showing an association between nut consumption and a reduced risk of coronary heart disease (CHD). Some evidence has emerged recently to suggest health-protective benefits of nuts other than CHD. Frequent nut intake probably reduces risk of diabetes mellitus among women; but its effects on men are unknown. Evidence on the anticarcinogenic effects of nuts is somewhat limited because studies in the past 2 decades have examined only 3 tumor sites; and the benefits appear to be manifested only in women. However; the protective benefits of frequent nut consumption on gallstone diseases are observed in both sexes. Long-term nut consumption is linked with lower body weight and lower risk of obesity and weight gain. A dietary pattern or score that includes nuts is consistently related with beneficial health outcomes; and this provides an indirect evidence of the salutary benefits of nut consumption. More longitudinal studies are needed to clarify the possible effects of nuts on diseases other than CHD.
Effects of peanut processing on body weight and fasting plasma lipids.
Peanuts and peanut butter are commonly consumed as a snack; meal component and ingredient in various commercial products. Their consumption is associated with reduced CVD risk and they pose little threat to positive energy balance. However; questions have arisen as to whether product form (e.g. whole nut v. butter) and processing properties (e.g. roasting and adding flavours) may compromise their positive health effects. The present study investigated the effects of peanut form and processing on two CVD risk factors: fasting plasma lipids and body weight. One hundred and eighteen adults (forty-seven males and seventy-one females; age 29.2 (sd 8.4) years; BMI 30.0 (sd 4.5) kg/m2) from Brazil; Ghana and the United States were randomised to consume 56 g of raw unsalted (n 23); roasted unsalted (n 24); roasted salted (n 23) or honey roasted (n 24) peanuts; or peanut butter (n 24) daily for 4 weeks. Peanut form and processing did not differentially affect body weight or fasting plasma lipid responses in the total sample. However; HDL-cholesterol increased significantly at the group level; and total cholesterol; LDL-cholesterol and TAG concentrations decreased significantly in individuals classified as having elevated fasting plasma lipids compared with those with normal fasting plasma lipids. These observations suggest that the processing attributes assessed in this trial do not compromise the lipid-lowering effects of peanuts; and do not negatively impact body weight. Further studies are warranted to determine the effects of form and processing on other health risk factors.
Scientific evidence of interventions using the Mediterranean diet: A systematic review.
The Mediterranean Diet has been associated with greater longevity and quality of life in epidemiological studies; the majority being observational. The application of evidence-based medicine to the area of public health nutrition involves the necessity of developing clinical trials and systematic reviews to develop sound recommendations. The purpose of this study was to analyze and review the experimental studies on Mediterranean diet and disease prevention. A systematic review was made and a total of 43 articles corresponding to 35 different experimental studies were selected. Results were analyzed for the effects of the Mediterranean diet on lipoproteins; endothelial resistance; diabetes and antioxidative capacity; cardiovascular diseases; arthritis; cancer; body composition; and psychological function. The Mediterranean diet showed favorable effects on lipoprotein levels; endothelium vasodilatation; insulin resistance; metabolic syndrome; antioxidant capacity; myocardial and cardiovascular mortality; and cancer incidence in obese patients and in those with previous myocardial infarction. Results disclose the mechanisms of the Mediterranean diet in disease prevention; particularly in cardiovascular disease secondary prevention; but also emphasize the need to undertake experimental research and systematic reviews in the areas of primary prevention of cardiovascular disease; hypertension; diabetes; obesity; infectious diseases; age-related cognitive impairment; and cancer; among others. Interventions should use food scores or patterns to ascertain adherence to the Mediterranean diet. Further experimental research is needed to corroborate the benefits of the Mediterranean diet and the underlying mechanisms; and in this sense the methodology of the ongoing PREDIMED study is explained.
Short-term effects of a snack including dried prunes on energy intake and satiety in normal-weight individuals
The purpose of this study was to test the hypothesis that a preload including dried prunes consumed as a snack before a meal; compared to an isoenergetic and equal weighed bread product preload would: (a) have greater short-term effect on satiety measured by subsequent ad libitum meal intake; (b) induce greater satiety as assessed by visual analogue scales (VAS); and (c) reduce appetite for dessert offered shortly after lunch. Forty-five healthy; normal-weight subjects participated in this randomised within-subject crossover study. Statistical analysis of the results showed that when subjects consumed the preload that included dried prunes; also consumed less amount of dessert and had lower total energy intake at meal. Additionally; subjects' feeling of hunger; desire and motivation to eat; as assessed with the use of VAS; were lower at all time points between snack and meal. Since macronutrients content of both preloads were similar; the satiating power of prunes could be due to their relatively high fiber content. Identifying meal patterns and foods that promote satiety without increasing considerably the overall energy intake is very important. The addition of dried prunes to a snack seems to promote satiety besides providing valuable nutrients.
Food habits and body composition of Spanish elite athletes in combat sports [Article in Spanish]
Introduction: There is a scarcity of information about the dietary intake and food selection of combat sport people. Optimizing nutritional status; body weight; and body composition are key factors for their performance. Aim: The assessment of dietary intake; food habits; and body composition in elite combat sport people. Subjects and methods: 22 sportmen were recruited from the Spanish National Teams of Taekwondo; Judo; and Boxing. Food intake (FFQ); food habits and bodycomposition (DXA and Bioimpedance) were analyzed. Results and discussion: Weight and body composition of the individuals assessed were similar to that previously described; although almost half of them were moderately over their desired competition weight. A lower than the recommended intake of vegetables (77% of individuals); cereals; bread; rice; potatoes; and pasta (73%); while red meat and derivatives intake exceeded the recommendations. Their main preferences were pasta; meat; and cereals. Legumes; vegetables; and fish were their main dislikes. A statistically significant relationship between food preferences and intakes was only observed for legumes; yogurt; and nuts. The athletes reported that reducing the intake of biscuits and confectionery (68% of individuals); high-fat foods (36%); and/or bread (27%) would be a good dietetic strategy for losing weight. None of them reported that voluntary dehydration would be a good strategy for this purpose. Conclusions: food offer to which this sport people have access and their choices are adequate; although the intake of some food groups (vegetables; red meat and derivatives) does not follow the recommendations. Their body weight slightly exceeds their competition weight; what it is frequently found in these sports. Nevertheless; their knowledge about nutrition and dietetics applied to exercise are acceptable.
Nuts and healthy body weight maintenance mechanisms
Nuts are rich sources of multiple nutrients and phytochemicals associated with health benefits; including reduced cardiovascular disease risk. This has prompted recommendations to increase their consumption. However; they are also high in fat and are energy dense. The associations between these properties; positive energy balance and body weight raise questions about such recommendations. Numerous epidemiological and clinical studies show that nuts are not associated with weight gain. Mechanistic studies indicate this is largely attributable to the high satiety and low metabolizable energy (poor bioaccessibility leading to inefficient energy absorption) properties of nuts. Compensatory dietary responses account for 55-75% of the energy provided by nuts. Limited data suggest that routine nut consumption is associated with elevated resting energy expenditure and the thermogenic effect of feeding; resulting in dissipation of another portion of the energy they provide. Additionally; trials contrasting weight loss through regimens that include or exclude nuts indicate improved compliance and greater weight loss when nuts are permitted. Nuts may be included in the diet; in moderation; to enhance palatability; nutrient quality; and chronic disease risk reduction without compromising weight loss or maintenance.
The effect of a calorie controlled diet containing walnuts on substrate oxidation during 8-hours in a room calorimeter
OBJECTIVE: Dietary macronutrient proportions affect substrate utilization; but in practice people consume foods. We hypothesized that in overweight adults; a calorie controlled diet based on core foods and including walnuts may be advantageous in promoting greater use of fat stores. METHODS: This crossover study tested the effects of diet-related energy expenditure and fat oxidation in 16 overweight individuals over an 8-hour period. The 2 diets included breakfast and lunch meals during the measurement period and an evening meal the night before. They comprised core foods of bread/cereals; fruit; vegetables; milk/yogurt; and meat; and either walnuts (walnut diet) or olive oil (control diet). There was no difference in the energy and macronutrient composition of the diets in the measurement period. Energy expenditure; respiratory quotient (RQ); and macronutrient oxidation were assessed during two 8-hour stays in a room calorimeter facility. RESULTS: During the 8-hour measurement period; no difference in energy expenditure was noted between the diets; but a significant difference in RQ was observed between diets (control 0.908 +/- 0.046 vs. walnut 0.855 +/- 0.036; p = 0.029). Carbohydrate oxidation was lower and fat oxidation was higher during the walnut period than during the control period. CONCLUSIONS: A calorie controlled diet of core foods including walnuts may be advantageous in promoting the use of body fat stores; at least under acute conditions.
The effect of including a conventional snack (cereal bar) and a nonconventional snack (almonds) on hunger; eating frequency; dietary intake and body weight
BACKGROUND: With the increasing prevalence of being overweight and obesity; dietary strategies to curb hunger levels and increase satiety at lower energy intakes are sought. The frequency of eating and type of snack may influence total energy intake. The present study aimed to assess the impact of providing either a conventional snack (cereal bar) or a nonconventional snack (almonds) on eating frequency; hunger rating; dietary intake; body weight and blood lipids. METHODS: Forty-five healthy men (aged 25-50 years; body mass index = 25-35 kg m(-2)) were recruited and allocated to a control; cereal bar or almond snack group. Two packets of cereal bars and almonds were introduced for 12 weeks to the cereal bar group and the almond snack group; respectively. Dietary intakes and eating frequency were assessed by 4-day unweighed diet diaries; visual analogue scales were used to assess hunger ratings; and fasting blood parameters (i.e. glucose; insulin; total cholesterol; triglycerides; low-density lipoprotein cholesterol and high-density lipoprotein cholesterol) were measured at baseline; 6 and 12 weeks. In addition; anthropometric measures (height; weight; skinfold thickness; waist and hip circumference) were measured at baseline; 6 and 12 weeks. RESULTS: The present study found no significant change in the eating frequency within groups at 12 weeks. However; the almond snack group had a significantly higher eating frequency than the control group (P < or = 0.05) and cereal bar group (P < or = 0.01). This did not result in higher energy intake; body weight or percentage body fat in the almond snack group. CONCLUSION: The present study demonstrated that snacking on almonds; in comparison to cereal bars; promoted a higher eating frequency; but not a higher energy intake. Advice to snack on either almonds or cereal bars did not result in weight gain; suggesting that energy compensation took place.