WEIGHT MANAGEMENT
The cost associated with the health risk factors of obesity was $147 billion in 2008. Many people follow diet trends known to cause weight cycling, “yo-yo dieting.” Weight cycling increases health risk factors as hormones disrupt homeostasis when dietary caloric changes occur. This is a literary review analyzing the effects of total meal replacement (TMR), a fiber supplement (FS), and medium-chain triglyceride (MCT) on weight loss. TMRs are convenient and have been found to alter food cravings. They have a significant impact on weight reduction as compared to low caloric food intake. FSs reduce energy uptake and provide a feeling of satiety, this reduces food consumption and increases weight loss. FSs stabilize hormones that are disrupted during reduced caloric food intake. MCTs are absorbed directly into the bloodstream providing quick energy and increased thermogenesis. These three weight reduction methods provide a safe and effective way to reduce weight. Studies show that behavioral modification supports the transition from supplementation to balanced food intake and increases the success of long-term weight loss.
In 2009 over 80 million people were considered obese, 40% of the population. Obesity increases the risk of type 2 diabetes, hypertension, hyperlipidemia, and coronary artery disease. The national economic cost in 2008 for obesity was $147 billion (Krishnaswami et al., 2018). Over the past thirty years, caloric intake has increased due to portion size, and the replacement of whole foods by processed empty calorie foods.
Many people are diet junkies, ready to jump on the bandwagon for the next miracle diet that will shed unwanted pounds while continuing to eat unhealthily. This behavior causes weight cycling, referred to as “yo-yo dieting,” which increases health risk factors associated with body composition, body fat distribution, and energy expenditure (Insel, Ross, McMahon, & Bernstein, 2017). Hormones disrupt homeostasis when dietary caloric changes occur, this can continue for up to one year after weight loss (Clifton, 2017). The resting metabolic rate decreases in long-term caloric restriction and weight loss. Losing weight and then maintaining the weight loss puts an end to weight cycling. Long-term weight maintenance correlates with the high thermic effect and satiety of protein, high fiber, low caloric foods, and an increase in polyunsaturated fat intake, found in plant and animal foods. Success for long-term stability dramatically increases after two to five years of maintained weight loss (Clifton, 2017).
This literary review focuses on three weight loss methods; TMR, FS, and MCTs. TMRs are convenient and reduce the choices and temptations that often occur with low-caloric menu planning. They often contain added vitamins and minerals. Patients can lose up to 50 pounds in eighteen to twenty-four weeks on TMRs (Obesity Action Coalition, 2018). Dietary fiber consists of a range of indigestible dietary carbohydrates that increase satiation and regulate hormone signaling related to satiation (Chew & Brownly, 2018). Increasing fiber intake should be gradual as it may cause abdominal cramps, gas, bloating, diarrhea, or constipation (Insel et al., 2017).
MCTs are absorbed directly into the bloodstream. There are four different types of MCTs, 6 carbon - caproic acid, 8 carbon - caprylic acid, 10 carbon - capric acid, and 12 carbon - lauric acid. Coconut oil is a combination of all four of the fatty acids, with 40% being lauric acid. Caprylic and capric fatty acids increase ketone levels more efficiently than lauric and caproic acid. Caprylic acid converts to ketones more rapidly than capric. Ketones suppress ghrelin and other hunger-related brain triggers. MCTs are used for energy rather than stored as fat, enhancing thermogenesis and fat oxidation. The initial intake of MCTs should be limited to one teaspoon and combined with another type of fat (nuts or ghee); as tolerance increases up to four tablespoons a day may be consumed (Mercola, 2016). MCTs are a source of concentrated energy that increases thermogenesis. Total meal replacement, fiber supplements, and medium-chain triglycerides increase weight loss.
Thirty-two male and female subjects participated in a randomized two-group repeated measures dietary intervention study conducted by Kahathuduwa et al. (2018). They were divided into two groups, one group followed a TMR diet, and the other group consumed a reduced-calorie typical diet. Both groups were instructed to intake a total of 1120 kcal/day for three weeks. The researchers analyzed brain activity and found that food-cue reactivity regulating energy balance, the dopaminergic reward system, and regions that execute intake behavior were affected with TMR extended calorie restriction (ECR). Reduced body weight was significantly higher in the TMR, as was the reduction of overall food cravings.
A 52-week multicenter, open-label randomized controlled trial in adults with a BMI of 30-55 kg/m2 was conducted by Rothberg et al. (2018). The study consisted of 330 participants divided into two groups. The groups followed either the OPTIFAST Program (OP), a total meal replacement diet with 800-989 kcal/day, or a food-based reduced-energy diet consisting of 500 to 750 kcal/day, both groups were supported with behavioral modification. There was a substantially higher weight loss in the OP group. At 26 weeks weight loss were 12.2% for the OP group and 5.9% for the food-based group. At 52 weeks weight loss were 10.3% for the OP group and 5.5% for the food-based group.
Krishnaswami et al. (2018) analyzed the medically supervised weight management program initiated by Kaiser Permanente Care Management Institute in Oakland, Ca. which consisted of 10,695 participants. Participants followed an eighty-two-week weight loss program broken down into three phases. Phase 1, 16 weeks, consisted of a 960 kcal/d TMR diet of OP shakes or soups. Phase 2, through week 30, transitioned the participant from TMR to a 1200 kcal/d food diet plan. Phase 3, through week 82, focused on maintenance of weight loss through weekly participation in group behavior meetings. Participants were followed for five years. The peak weight loss was found at 16 weeks at 17.3 kg (38.1 lbs.). Long-term weight loss at 5 years was reported at 6.5 kg (14.3 lbs.). Forty-eight percent of the participants maintained a 5% weight loss, and 33% sustained a 10% weight loss. The researchers believe that the long-term weight loss correlated with the significant weight loss in Phase 1 utilizing TMR which demonstrated an average of 15.5% weight loss.
Chew and Brownlee (2018) conducted a systematic review of randomized controlled trials analyzing various fiber supplements. Thirty-three studies with a combined sample size of 1625 participants aged 18 to 65 and overweight were included in the reviews. The researchers found that fiber changed the metabolism of the body by regulating the satiation signaling hormones, decreasing energy uptake, and increasing energy expenditure. Studies showed a significant weight loss for chitosan and a nonsignificant weight loss for glucomannan.
Pal, Ho, Gahler, and Wood (2017) conducted a randomized trial on 127 participants to determine the effect of two different fiber supplements on insulin, glucose, and lipids in overweight and obese adults during a 12 month period. Ninety-three participants completed the trial. The groups either took 15g PolyGlycopleX (PGX), psyllium (PSY), or rice flour (RF) at 5g doses mixed with water five to ten minutes before meals. Psyllium is a soluble fiber. PGX is a highly viscous functional non-starch polysaccharide complex made from konjac glucomannan, sodium alginate, and xanthan gum. PGX swells in the stomach and increases feelings of satiety. The researchers found that the PGX group had a significant decrease in fat and protein intake which leads to substantial weight loss, lipid, insulin, and glucose reductions
Solah et al. (2017) studied the effect of PGX on body weight and composition, frequency of eating, and dietary intake on 118 participants for twelve weeks with a BMI of 25-35 kg/m2. The only change required in the eating pattern was the addition of the supplement. The participants were divided into three groups, group one took 4.5g PGX soft gels (PGXS), group two 5g PGX granules (PGXG), and group three 5g RF, three times a day with a glass of water before meals. They were instructed to reduce doses for week one and increase in week two and again in week three if they suffered from diarrhea, bloating, or flatulence. Variables were measured at baseline and at 12 weeks. The PGXG group had a significant reduction in body weight (-1.4kg [3.1 lbs.], waist circumference (2.5cm), and the number of eating occasions (-1.4). PGX was identified as improving satiety, lipidemia, and glycemia.
Sharafi, Alamdari, Wilson, Leidy, and Glynn (2018) conducted a randomized, double-blind placebo-controlled crossover study to determine short-term effects between a high-protein, high-fiber beverage (HP/HFb) and an isocaloric lower-protein, lower-fiber (LP/LFb) placebo beverage on appetite and energy intake in healthy adults. The researchers found that the HP/HFb group had greater reductions in the postprandial desire to eat and hunger compared with the LP/LFb group.
A meta-analysis conducted by Rial, Karelis, Bergeron, & Mounier (2016) found significant evidence that MCTs, specifically coconut oil, were associated with higher energy expenditure and improved the cardiometabolic and anthropometric profiles of women with visceral obesity. The researchers were interested in the profile differences between metabolically healthy but obese (MHO) and metabolically unhealthy obese (MUHO) people. The research emphasized the increase in high energy expenditure in people consuming MCTs is a significant factor in losing weight.
A systematic review, meta-analyses, and meta-regression conducted by Quatela, Callister, Patterson, and MacDonald-Wicks (2016) found that diet-induced thermogenesis (DIT) was significantly influenced by macronutrient composition. The study found that macronutrient composition which included MCT as the dietary fat, induced thermogenesis.
A randomized, double-blind, cross-over study conducted by LaBarrie and St-Onge (2017) found no evidence in the thermic effect on food (TEF) baked with 1g of coconut oil versus corn oil in two meals. The study consisted of fifteen children from the age of 13 to 18 years old. Previous studies with a minimum dose of 18g of MCT for periods of 4 to 16 weeks have shown a significant increase in TEF. The researchers believed that they did not select the proper dosage or intake time of MCT to be effective.
People try many different diets over their lifetime setting a pattern of weight cycling. Weight cycling disrupts hormones affecting the homeostasis of the body. Rapid and substantial weight loss is achievable by TMR, FSs, and consumption of MCTs. Long-term weight stability is supported by behavioral modification.
TMRs are successful in reducing temptations and promoting rapid weight loss. TMR suppresses food cravings and regulates energy balance. The dopaminergic reward system and areas of the brain that execute intake behavior are affected more with TMR than with a food-based low-calorie diet. TMR is associated with reduced food-cue reactivity in the brain and allows the person to gain better control over food intake. A TMR diet consisting of a caloric intake between 800 to 1100 kcal/day promotes significantly more weight loss than reduced-calorie food diets with the same caloric intake. Two of the TMR studies followed the OP, which is a medically supervised weight management program that starts with TMR and transitions into self-prepared foods for long-term weight management. Studies show a significant initial weight loss with TMR, from 12.2% to 15.5% as well as a reduction in risk factors for diabetes and an increased prevalence of long-term weight loss. Studies show that behavior modification is a significant factor in transitioning from TMR to healthy food intake and sustains long-term weight loss.
Fiber is indigestible and decreases energy uptake by interfering with the digestion and absorption of macronutrients. Studies show that 15g of fiber supplementation daily decreases food intake. Gradually increasing dosage will reduce side effects. PGX and chitosan supplementation were found to increase weight loss over meal plans without fiber supplementation.
MCTs, induce thermogenesis and energy expenditure. Resting metabolic rate is decreased during long-term caloric restriction and weight loss. Studies show that MCTs increase the resting metabolic rate. Conflicting information was found in one study which did not show an increase in resting energy expenditure in children. It was believed that the dosage of MCT was not correct in the study. Studies show that a minimum of 18g of MCT per day for 4 to 16 weeks have increased the TEF. MCTs are readily absorbed by the intestinal cells and have greater solubility. MCTs are transported directly to the liver and metabolized to generate energy. They induce thermogenesis and reduce lipogenesis.
Many different diets are effective for quick weight loss. The optimal diet is the one that a person can stick to long-term to achieve the goal weight. TMR, FS, and MCTs can increase weight reduction. TMRs reduce food cravings and provide the caloric needs, essential vitamins, and minerals for the body to produce energy. FS helps control hormones related to hunger and promotes a feeling of satiety. MCTs increase thermogenesis and generate quick energy. Behavioral modification supports weight loss in the transition from TMR to healthy food intake and maintenance of long-term weight loss. Long-term weight stability dramatically increases after two to five years of maintained weight loss.
Further studies analyzing the effects of combining these three methods of weight loss may provide valuable information. The findings could be used to develop a diet that would induce initial significant weight loss, reduce cravings, give a feeling of satiety, and increase thermogenesis. These factors would increase the short-term and long-term success of the patient.
References:
Chew, K.Y. & Brownlee, I.A. (2018). The impact of supplementation with dietary fibers on weight loss: A systemic review of randomised controlled trials. Bioactive Carbohydrates and Dietary Fibre. 14, 9-19.
Clifton, P. (2017). Assessing the evidence for weight loss strategies in people with and
without type 2 diabetes. World Journal of Diabetes. 8(10).
Insel, P., Ross, D., McMahon, K., & Bernstein, M. (2017). Nutrition (6th Ed.). Burlington,
MA: Jones & Bartlett Learning.
Kahathuduwa, C. N., Davis, T., O’Boyle, M., Boyd, L. A., Chin, S., Paniukov, D., & Binks, M.
(2018). Effects of 3-week total meal replacement vs. typical food-based diet on human
brain functional magnetic resonance imaging food-cue reactivity and functional
connectivity in people with obesity. Appetite. 120, 431-441. Retrieved from:
https://www.ncbi.nlm.nih.gov/pubmed/28958900
Krishnaswami, A., Ashok, R., Sidney, S., Okimura, M., Kramer, B., Hogan, L.,…Smith, W.
(2018). Real-World effectiveness of a medically supervised weight management program in
a large integrated health care delivery system: Five-Year outcomes. The Permanente
Journal. 17(082).
LaBarrie, J. & St-Onge, M. (2017). A coconut oil-rich meal does not enhance thermogenesis
compared to corn oil in a randomized trial in obese adolescents. Insights Nutrition
Metabolism. 1(1), pp 30-36. Retrieved from:
https://www.ncbi.nlm.nih.gov/pubmed/28758166
Mercola, J. (2016). The many health benefits of MCT oil. Retrieved from:
https://institutoflash786.org/2016/10/24/the-many-health-benefits-of-mct-oil/
KMiller 4/2018