Here is a list of several food constituents that have been tested and recommended for controlling obesity.
1. Whole Grains:
Whole grain (WG)-rich diets are purported to have a variety of health benefits, including a favorable role in body weight regulation. Epidemiological studies consistently demonstrated that higher intakes of WG, but not refined Grains, are associated with lower BMI and/or reduced risk of obesity.
BMI and weight gain were inversely associated with intake of breakfast cereals (major source of whole and refined grains, independently of other risk factors. Slavin (2003; 2004) reported that the few whole-grain feeding studies that are available show improvements in biomarkers with whole-grain consumption, such as weight loss, blood lipid improvement and anti-oxidant protection.
Moreover, whole-grain RTE oat cereal as part of a dietary program for weight loss had favorable effects on fasting lipid levels and waist circumference also. O’Neil et al (2010) confirmed that adults who consumed the most servings of whole grains had lower body weight measures. They also suggested that fiber in whole grain foods may mediate associations with weight measures in adults, and hence intake of whole grain foods should be encouraged by health professionals.
Fordyce-Baum et al (1989) found that an air-expanded whole-wheat protein product (SNW) consumed by moderately obese women as a meal substitute for 12 weeks resulted in safe and effective weight reduction and serum lipid modification.
2. Red Cowpea (Adzuki Bean):
The animal study by Kitano-Okada et al (2012) showed that adzuki bean extracts improved lipid metabolism in both normal and high-fat diet groups. Adzuki bean extract treatment in the high-fat group resulted in significant reductions in total hepatic lipid accumulation and lipid secretion into the feces.
Incubation of adipocytes with adzuki bean extract significantly decreased triglyceride accumulation, glycerol phosphate dehydrogenase activity and inflammatory responses without affecting cell viability thus demonstrating that adzuki bean extract has high potential to serve as a natural anti-obesity agent.
3. Oats (Avena Sativa):
Recent research suggests that children in the age group of 2-18 years old who have a constant intake of oatmeal lowered their risk of obesity. Research also confirmed that the children who ate oatmeal were 50 per cent less likely to become overweight, when compared to those children that did not. Some studies suggested that protein has a thermo genic effect that boosts metabolism, which may aid weight loss.
Beck et al. (2009) found a significant dose response, with a positive correlation between the amount of beta-glucan consumed and PYY area under the curve (r (2) = 0.994, P = 0.003). The optimal dose of beta-glucan appears to lie between 4 and 6 g, with the effects on PYY (an anorexigenic hormone) mediated by viscosity and concentration. Subsequent meal intake decreased by greater than 400 kJ with higher beta-glucan dose (>5 g). Improved satiety by beta-glucan and release of cholecystokinin are likely to be part of the mechanisms.
The average energy intake (-13 per cent, p < 0.05) and body weight gain were lower with increasing β-glucan over 6 wk with acute suppression of energy intake over 4 h. The highest β-glucan diet significantly increased plasma PYY, with suppression of Arc NPY mRNA.
4. Pearl Millet/Fox Tail Millet/Finger Millet (Panicum Miliaceum L.):
Dietary intake of whole grains reduces the incidence of chronic diseases such as obesity, diabetes, cardiovascular disease, and cancer. Consumption of whole-grain RTE oat cereal as part of a dietary program for weight loss had favorable effects on fasting lipid levels and waist circumference. Whole grains such as foxtail millet, hog millet, sorghum, Job’s tears, and barley have been used as ingredients in traditional Korean food.
In a preliminary study hog millet (Panicum miliaceum L.) extract showed the highest anti-adipogenic activity by effectively inhibiting lipid synthesis, as measured by lipid-detecting Oil Red O staining, among extracts of nine types of cereal grains in a 3T3-L1 cell system. Panicum miliaceum L. extract (PME) exhibited the highest anti-lipogenic activity in 3T3-L1 cells among extracts of nine different cereal grains tested.
Also effectively decreased body weight, liver weight, blood triglyceride and total cholesterol levels (P < 0.05) compared to obese ob/ob mice on a normal diet. Hepatic lipogenic-related gene (PPARα, L-FABP, FAS, and SCD1) expression decreased, whereas lipolysis-related gene (CPT1) expression increased in animals fed the 1 per cent PME diet (P < 0.05).
Long chain fatty acid content and the ratio of C18:1/C18:0 fatty acids decreased significantly in adipose tissue of animals fed the 1 per cent PME diet. PME is useful in the chemoprevention or treatment of obesity and obesity-related disorders. Thus they suggest that PME is useful in the chemoprevention or treatment of obesity and obesity-related disorders.
5. Flaxseeds (Linum Usitatissimum):
Dietary fibers have been proposed to play a role in cardiovascular risk as well as body weight management. Flaxseeds are a good source of dietary fibers, and a large proportion of these are water-soluble viscous fibers. Kristensen et al. (2012) observed that both flax drink and flax bread decreased plasma total and LDL-cholesterol and increased fat excretion, but suggested that the food matrix and/or processing may be of importance. Viscous flaxseed dietary fibers may be a useful dietary agent for lowering blood cholesterol and potentially play a role in energy balance.
6. Soya (Glycine Max):
Soybean (SB) is known to have an anti-obesity effect. A tetra peptide in soy protein isolate and hydrolysate showed anti-obesity effect in genetically obese mice by reducing perirenal fat mass and plasma glucose level. The beneficial effects of this protein food are attributed to its high content of isoflavones mainly genistein and daidzein.
According to them the anti-obesity effect of soy protein and its isoflavones appears to be due to the modulation of pancreatic insulin and anti-oxidative actions and through long-term substitution of animal proteins by vegetable proteins in low-calorie diet.
Kwon et al. (2007) indicated that the anthocyanins in black soybean seed coats have an anti-obesity effect, which can reverse the effects of HFD on body weight, adipose tissue weight, and serum lipid contents. The black soybean anthocyanins suppressed the high fat diet (HFD)-induced weight gain in liver and tended to decrease the weights of epididymal and perirenal fat pads.
They improved the lipid profile, by significantly reducing the levels of serum triglyceride and cholesterol, while increasing the high-density lipoprotein-cholesterol concentration. Blake et al. (2011) confirmed that the consumption of dietary isoflavones in rats has body weight controlling effects.
A double-blind, randomized clinical trial on the effect of consumption of supplemental whey protein (WP), soy protein (SP), and an iso-energetic amount of carbohydrate (CHO) on body weight and composition in free-living overweight and obese but otherwise healthy participants showed the body weight and fat mass of the group consuming the WP to be lower by 1.8 kg (P < 0.006) and 2.3 kg (P < 0.005), respectively than the group consuming CHO. Lean body mass did not differ among any of the groups. Waist circumference was smaller in the participants consuming WP than in the other groups.
Compared with the high GI/low-protein SB, a high soy protein meal replacement with a low GI was associated with lower glycemia and insulinemia and relatively higher fat oxidation in the postprandial period. Together with a favorable course of appetite-regulating hormones, this could further help to explain the beneficial role of meal replacement regimens high in soy protein for weight reduction and improvement of metabolic risk factors.
Recent studies suggest that calcium metabolism and perhaps other components of dairy products may contribute to shifting the energy balance and thus play a role in weight regulation. Faghih et al. (2011) observed that weight reductions in high milk, soy milk, calcium supplement and control groups to be 4.43 ± 1.93(kg), 3.46 ± 1.28(kg), 3.89 ± 2.40(kg) and 2.87 ± 1.55(kg), respectively.
The greatest changes were seen in the high dairy group in all variables as compared to soya milk or calcium groups. On the other hand Lukaszuk et al. (2007) suggested that 720 mL of either soy milk or skim milk daily is needed to optimize the weight loss effects of calcium. In their study, the subjects followed an energy-restricted diet.
Soya milk as well as skim milk groups experienced reductions in kilogram weight (4.27 ± 2.05 vs 3.76 ± 2.25; p = 0.668), body fat per cent (1.30 ± 1.37 vs 1.87 ± 1.45; p = 0.464), and abdominal circumference (11.28 ± 5.23 vs 8.66 ± 2.51; p = 0.259) while attenuating losses of fat-free mass (1.12 ± 1.29 vs 0.43 ± 1.12; p = 0.299) during the 8-week study. There were no significant differences in weight, fat per cent, abdominal circumference, and fat-free mass between groups.
Kwak et al. (2012) confirmed that Doenjang (a fermented soya product) was more effective than non-fermented soybeans in preventing diet-induced visceral fat accumulation, possibly because of its greater effects on stimulation of carnitine palmitoyltransferase-1 activity and suppression of fatty acid synthase activity. These effects may be due in part to the higher content of aglycone isoflavones in doenjang. Soy-derived isoflavones potentially protect against obesity and depression.
7. Gurmar (Gymnema Sylvestre):
Gymnema sylvestre is a woody climbing plant that grows in the tropical forests of central and southern India. Its active constituents include two resins (soluble in alcohol), gymnemic acids, saponins, stigma sterol, quercitol, and the amino acid derivatives betaine, choline and trimethylamine. The active principle of this plant is gymnemic acid. It is a mild diuretic and has the property of abolishing the taste of sugar and neutralising the excess sugar present in the body.
Preuss et al. (2004 a; b; 2005) showed that the combination of HCA-SX, NBC and Gymnema sylvestre can serve as an effective and safe weight-loss formula that can facilitate a reduction in excess body weight and BMI, while promoting healthy blood lipid levels and increasing serum leptin and serotonin levels and fat oxidation more than placebo.
Luo et al. (2007) also reported that supplementation with gymnemate from Gymnema sylvestre promoted weight loss by its ability to reduce hyper-lipidemia, which was no withdrawal rebound – an important discovery. Thus, supplementation with gymnemate could be considered a novel therapeutic tool for weight management, especially in multifactor syndrome.
8. Bitter Gourd/Bitter Melon (Momordica Charantia):
Bitter melon has been shown to ameliorate diet-induced obesity and insulin resistance. Extracts of bitter gourd inhibited the proliferation on 3T3-L1 preadipocytes in a dose-dependent manner having the most toxic effect with an LC50 value of 1.7 mg/mL. The extract also inhibited the differentiation of preadipocytes in a time-and dose-dependent manner. These anti-obesity-related bioactivities were again attributed to the potential synergistic effects of flavonoids.
Bitter gourd seed oil is effective in attenuating body fat accumulation through mechanisms associated with protein kinase activation and programmed cell death in the white adipose tissue. Rats fed 5 per cent lyophilized BM powder showed significantly lower mRNA levels of fatty acid synthase, acetyl-CoA carboxylase-1, lipoprotein lipase and adipocyte fatty acid-binding protein than the high fat group (P < 0.05).
Hence, Huang et al. (2008) concluded that bitter gourd can suppress the visceral fat accumulation and inhibit adipocyte hypertrophy, which may be associated with markedly down regulated expressions of lipogenic genes in the adipose tissue. Yama et al. (2010) also demonstrated that bitter gourd caused dose-dependent reductions in body weight and serum cholesterol concentration in male Sprague-Dawley rats. It may, therefore, be useful in controlling body weight gain in individuals of growing age as well as be a potential agent in the management of overweight and obesity.
Bitter gourd appears to have multiple influences on glucose and lipid metabolism that strongly counteract the untoward effects of a high fat diet. A general decrease in tissue fat accumulation, mediated in part, by enhanced sympathetic activity and lipolysis by bitter gourd.
Bitter gourd reduced adiposity in rats fed a high fat diet. BM-supplemented rats had lower energy efficiency (g weight gained/ kJ consumed), visceral fat mass, serum glucose, and insulin resistance index, but higher plasma norepinephrine than un-supplemented rats. Hepatic and skeletal muscle triglyceride concentrations were lower in supplemented HF diet-fed rats than in un-supplemented High Fat diet-fed rats.
According to Chen and Li (2005), chronic feeding of bitter gourd leads to a general decrease in tissue fat accumulation and that such an effect is mediated in part by enhanced sympathetic activity and lipolysis. Bitter gourd or its bioactive ingredient(s) could be used as a dietary adjunct in the control of body weight and blood glucose.
Bitter gourd could influence dual PPAR alpha/PPAR gamma expression and the mediated gene expression. It is effective in ameliorating insulin resistance and visceral obesity. Its juice is a potent inhibitor of lipogenesis and stimulator of lipolysis activity in human adipocytes. The juice may therefore prove to be an effective complementary or alternative therapy to reduce abiogenesis in humans.
9. Almonds:
The fat content and energy density of almonds raise concerns that chronic consumption will promote weight gain. But Hollis and Mattes (2007) confirmed that ten weeks of daily almond consumption did not cause a change in body weight predominantly due to compensation for the energy contained in the almonds through reduced food intake from other sources. Moreover, inefficiency in the absorption of energy from almonds was documented (P < 0.05).
No changes in resting metabolic rate, thermic effect of food or total energy expenditure were noted. A daily 1440 kJ serving of almonds, sufficient to provide beneficial effects on cardiovascular risk factors, may be included in the diet with limited risk of weight gain. Zaveri and Drummond (2009) also demonstrated that snacking on almonds, in comparison to cereal bars, promoted a higher eating frequency, but not a higher energy intake, but did not result in weight gain, suggesting the possibility of energy compensation.
Wien et al. (2003) compared a formula-based LCD enriched with 84 g/day of almonds (almond low calorie diet-39 per cent total fat, 25 per cent MUFA and 32 per cent carbohydrate as per cent of dietary energy) or self-selected complex carbohydrates (CHO-LCD; 18 per cent total fat, 5 per cent MUFA and 53 per cent carbohydrate as per cent of dietary energy) featuring equivalent calories and protein.
The almond-enriched low calorie diet (LCD) improved a preponderance of the abnormalities associated with the metabolic syndrome. Although both dietary interventions were effective in decreasing body weight beyond the weight loss observed during long-term pharmacological interventions. The almond-LCD group experienced a sustained and greater weight reduction for the duration of the 24-week intervention. Thus, almond supplementation of a formula-based LCD is a novel alternative to self-selected complex carbohydrates and has a potential role in reducing the public health implications of obesity.