|
Elusive Weight-Loss Success
The experts Today's Dietitian spoke with agree that while the 3,500-calories-per-pound rule does seem to work fairly well in the short term and for those who want to lose only a few pounds, the logic begins to fall apart over the long term, especially for those trying to lose a significant amount of weight. Dietitians know that as an individual loses weight, the body's energy requirements decrease, but the dynamic physiological adaptations that occur never have been quantified or figured into the 3,500-calorie rule.4 The most serious error of the 3,500-calorie rule is its failure to account for dynamic changes in energy balance that occur during a dieting intervention.5 Also not taken into account: gender, the fact that eating and exercise habits may change over time, and poor compliance, all of which can affect weight loss. Because of this, the experts say, the 3,500-calorie-per-pound approach significantly overestimates how much weight people will lose over time, setting them up for disappointment when weight loss slows or stops altogether.1 In other words, the body adapts and lifestyles change in myriad ways that minimize or even eradicate the impact of reduced calorie intake and, until recently, there has been no way to predict how consuming fewer calories may affect the rate of weight loss among individuals trying to lose weight, especially when the goal is to lose more than just a few pounds.
The new complex weight-loss formulas factor in the drop in metabolic rate that occurs over time as body mass decreases. After applying the formulas to individuals, a main conclusion Thomas and other researchers have drawn isn't a popular one—that people generally plateau early in the weight-loss process, not because of a metabolic slowdown, although that does occur, but because they don't adhere to calorie-reduced diet plans consistently long term.4,6
"If a plateau is reached within six months, then in all likelihood, the person is no longer strictly adhering to the diet," says Carson C. Chow, PhD, a senior investigator in the mathematical biology section of the National Institutes of Health (NIH). Six to nine months is the typical timeline for dieters to reach the dreaded plateau, but "given that body weight changes so slowly, it could be stretched out to a year," Chow says. The new formulas allow clinicians to see what realistically can be expected based on the individual's weight, age, gender, and physical activity, and close monitoring allows for adjustments in the predictive formula.7
Where exactly does exercise fit in? The effect of physical activity on the rate of weight loss isn't clear. However, research suggests that the small amount of weight loss sometimes seen in exercise intervention studies isn't due to exercise's lack of effect on weight loss, but it's a result of not getting enough exercise prescribed,6 and that's compounded by an increase in calorie intake—in other words, not sticking to the prescribed reduced-calorie diet long term.1 The ratio of macronutrients in the diet, specifically the ratio of protein to carbohydrates and fat, has been endorsed as a way to promote weight loss. However, little effect has been demonstrated in the short term.
Yet, according to Kevin Hall, PhD, a senior investigator in the mathematical biology section of the NIH, not enough is known about the long-term effects of varying macronutrient diet composition.4 As a result, the ratio of macronutrients in the diet isn't included in the new weight-loss prediction formulas.
New Weight-Loss Math
To access the programs and apps for assessing the weight-loss trajectory of clients and patients, Hall and colleagues at the NIH have developed the Body Weight Simulator, available at www.niddk.nih.gov/research-funding/at-niddk/labs-branches/LBM/integrative-physiology-section/body-weight-simulator/Pages/body-weight-simulator.aspx. At first glance, it may not look that different from other weight-loss predictors, but a tremendous amount of mathematical calculations have gone into its development. Plug in your client's information (weight, height, activity level, goal weight, length of time to reach goal) and it will provide a calorie level for weight loss and a calorie level for maintenance. Thomas and her colleagues at Pennington Biomedical Research Center in Baton Rouge, Louisiana, also have developed a Single Subject Weight Change Predictor application for predicting weight loss, which can be found at http://pbrc.edu/research-and-faculty/calculators/sswcp. Using the Pennington online calculator, a 200-lb man aged 35 who cut 500 kcal/day from his diet would be expected to lose 23 lbs in one year vs 23 lbs in four months in accordance with the 3,500-calorie-per-pound rule.
Hall and Thomas agree that while there are several minor differences in their models, the predictions are similar. The NIH calculator allows for more detailed input about physical activity, and the Pennington model enables users to compare the newly calculated downward weight-loss trajectory, based on your input, with that of the 3,500-calorie-per-pound rule.
https://www.todaysdietitian.com/newarchives/111114p36.shtml
Diet Calendar Entry for 12 November 2019:
|
2442 kcal
|
Fat: 55.18g | Prot: 83.07g | Carb: 431.49g.
Breakfast: Natural Series 50G Plant-Based Organic Protein Peanut, Turmeric (Ground), The Ginger People Crystallized Ginger, Ocean Spray Craisins Dried Cranberries, Quaker Old Fashioned Oats, Bananas, Now Foods Psyllium Husk Powder, Hot Water, Coconut Secret Raw Coconut Aminos, Orange Juice, Whole Foods Market Nutritional Yeast, Now Foods Magnesium Citrate Powder, Ginger (Ground), Black Pepper, Dried Seaweed. Lunch: Sam's Club Orange Bell Pepper, Trader Joe's Chicken-less Mandarin Orange Morsels, Don Lee Farms Vegan Superfoods Burgers, Trader Joe's Organic Superfood Pilaf, Trader Joe's Handsome Cut Potato Fries. Dinner: Clif Bar Clif Bar Sweet & Salty - Caramel Toffee with Sea Salt. more...
|
|