scholarly journals Beyond “Counting Macros”: Are Common Fad Diets Nutritionally Adequate? An Examination of Their Micronutrient Content

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1823-1823
Author(s):  
Neal Malik ◽  
Serena Tonstad ◽  
Ella Haddad

Abstract Objectives We compared a high-fiber bean-rich diet with a low-carbohydrate diet in a randomized controlled trial to assess their effects on body weight, blood lipids and micronutrient adequacy. Methods One hundred and seventy-three women and men with a mean body mass index of approximately 36 kg · m−2 were randomized to a high-fiber bean-rich diet that achieved mean (SD) fiber intakes of 35.5 (18.6) g · day−1 for women and 42.5 (30.3) g · day−1 for men, or a low-carbohydrate diet (<120 g · day−1). Both diets were induced gradually over 4 weeks and included a 3-day feeding phase. Results After 52 weeks, the low-carbohydrate (n = 24) group tended to retain weight loss better than the high-fiber group (n = 30) (P = 0.06), although total cholesterol remained lower with the bean-rich diet (P = 0.049). The low-carbohydrate group consumed more vitamin K (P = 0.006), thiamin (P = 0.001), and niacin (P = 0.02) whereas those in the high-fiber group consumed more folate (P = 0.006), magnesium (P = 0.046) and copper (P = 0.017). Both groups consumed less than the RDA for vitamin D, vitamin E, calcium, magnesium and copper. Conclusions A high-fiber bean-rich diet was as effective as a low-carbohydrate diet for weight loss. However, both diets were deficient in micronutrients. These results may have implications for long-term disease risk and morbidity management. Funding Sources Lifestyle Center of America (Sulphur, OK).

Circulation ◽  
2013 ◽  
Vol 127 (suppl_12) ◽  
Author(s):  
Tian Hu ◽  
Kristi Reynolds ◽  
Lu Yao ◽  
Calynn Bunol ◽  
Yanxi Liu ◽  
...  

The long-term effects of low-carbohydrate diets on hormones related to appetite are unclear. We recruited a total of 148 study participants with a body mass index of 30 - 45 kg/m2 (Mean: 35.4 kg/m2) who were free of diabetes, cardiovascular diseases and kidney disease. The participants were randomly assigned to either a low-carbohydrate diet (<40 g/day; N=75) or a low fat (<30% energy from fat, <10% from saturated fat; N=73) diet. Two 24-hour dietary recalls were conducted at each clinic visit (0, 3, 6 and 12 months of the intervention). Participants met with a study dietitian weekly for the first month followed by group settings bi-weekly for 5 months then monthly for the subsequent 6 months. Each group was provided the same behavioral curriculum related to diet emphasizing portion control and eating habits. Total ghrelin and peptide YY were determined using radioimmunoassay methods. Of the study participants, 60 in the low-fat group (81.1%) and 59 in the low-carbohydrate group (79.7%) completed the entire intervention. The mean age was 46.8 years, 88.5% were women and 55.1% were African-Americans. The low-carbohydrate group lost approximately 3.5 kg more body weight than did the low-fat group (P value: 0.002) over the course of the intervention. Both diets decreased total peptide YY and ghrelin. Compared to low-fat diets, the low-carbohydrate diet resulted in a significantly greater decrease in total peptide YY at 6 (Net change: -6.8 ph/mL; P value: 0.04) and 12 months (Net change: -10.6 ph/mL; P value: 0.02). The changes in total ghrelin were not significantly different throughout the study. Our findings suggest that the low-carbohydrate diet did not result in a greater loss of appetite, compared to the low-fat diet.


2017 ◽  
Vol 313 (4) ◽  
pp. R347-R356 ◽  
Author(s):  
Hugh S. Winwood-Smith ◽  
Craig E. Franklin ◽  
Craig R. White

Long-term studies have found that low-carbohydrate diets are more effective for weight loss than calorie-restricted diets in the short term but equally or only marginally more effective in the long term. Low-carbohydrate diets have been linked to reduced glycogen stores and increased feelings of fatigue. We propose that reduced physical activity in response to lowered glycogen explains the diminishing weight loss advantage of low-carbohydrate compared with low-calorie diets over longer time periods. We explored this possibility by feeding adult Drosophila melanogaster a standard or a low-carbohydrate diet for 9 days and measured changes in metabolic rate, glycogen stores, activity, and body mass. We hypothesized that a low-carbohydrate diet would cause a reduction in glycogen stores, which recover over time, a reduction in physical activity, and an increase in resting metabolic rate. The low-carbohydrate diet reduced glycogen stores, which recovered over time. Activity was unaffected by diet, but metabolic rate was reduced, in the low-carbohydrate group. We conclude that metabolic depression could explain the decreased effectiveness of low-carbohydrate diets over time and recommend further investigation of long-term metabolic effects of dietary interventions and a greater focus on physiological plasticity within the study of human nutrition.


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1646-1646
Author(s):  
Faiza Kalam ◽  
Kelsey Gabel ◽  
Sofia Cienfuegos ◽  
Mark Ezpeleta ◽  
Vasiliki Pavlou ◽  
...  

Abstract Objectives Alternate day fasting (ADF) has been shown to lower body weight and improve subjective appetite by increasing fullness over time. What remains unknown, however, is whether carbohydrate restriction during ADF would provide additional weight loss benefits by helping to lower hunger as well. Accordingly, this study examined the effect of 6-months of ADF combined with a low carbohydrate diet on fasting and postprandial appetite ratings. The relationship between changes in appetite and body weight was also examined. Methods Adults with obesity (n = 31) participated in ADF (600 kcal “fast day” alternated with an ad libitum “feast day”) with a low-carbohydrate background diet (30% carbohydrates, 35% protein, and 35% fat). The 6-month trial consisted of a 3- month weight loss period followed by a 3-month weight maintenance period. Results Body weight (P &lt; 0.001) decreased by 5.5 ± 0.5% by month 3 (end of weight loss period) and by 6.3 ± 1.0% by month 6 (end of weight maintenance period). Subjective hunger and fullness did not change during the weight loss period, or the weight maintenance period. Hunger and fullness were not related to changes in body weight during the weight loss or weight maintenance periods. Fasting insulin decreased (P = 0.03) by − 24 ± 8% by month 6 relative to baseline. Fasting glucose and homeostatic model assessment of insulin resistance (HOMA-IR), remained unchanged over the course of the study. Conclusions These findings suggest that ADF combined with a low carbohydrate diet is an effective way of lowering body weight. However, these weight loss benefits are not related to improvements in hunger or fullness. Funding Sources Nestle Health Sciences.


Nutrients ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 211
Author(s):  
Faiza Kalam ◽  
Kelsey Gabel ◽  
Sofia Cienfuegos ◽  
Mark Ezpeleta ◽  
Eric Wiseman ◽  
...  

Background: Alternate day fasting combined with a low carbohydrate diet (ADF-LC) is an effective weight loss regimen. Whether the weight loss induced by ADF-LC can improve sleep, remains unknown. Objective: This study examined the effect an ADF-LC diet on sleep quality, duration, insomnia severity and the risk of obstructive sleep apnea. Methods: Adults with obesity (n = 31) participated in ADF (600 kcal “fast day”; ad libitum intake “feast day”) with a low-carbohydrate diet (30% carbohydrates, 35% protein, and 35% fat). The 6-month trial consisted of a 3-month weight loss period followed by a 3-month weight maintenance period. Results: Reductions in body weight (−5 ± 1 kg, p < 0.001) and fat mass (−4 ± 1 kg, p < 0.01) were noted during the weight loss period, and these reductions were sustained during the weight maintenance period. Lean mass and visceral fat remained unchanged. The Pittsburgh Sleep Quality Index (PSQI) score indicated poor sleep quality at baseline (6.4 ± 0.7) with no change by month 3 or 6, versus baseline. ISI score indicated subthreshold insomnia at baseline (8.5 ± 1.0), with no change by month 3 or 6, versus baseline. The percent of subjects with high risk of obstructive sleep apnea at baseline was 45%, with no change by month 3 or 6. Wake time, bedtime, and sleep duration remained unchanged. Conclusion: The ADF-LC diet does not impact sleep quality, duration, insomnia severity or the risk of obstructive sleep apnea in adults with obesity.


Circulation ◽  
2014 ◽  
Vol 129 (suppl_1) ◽  
Author(s):  
Yasuyuki Nakamura ◽  
Nagako Okuda ◽  
Tomonori Okamura ◽  
Aya Kadota ◽  
Naoko Miyagawa ◽  
...  

Background: Long-term safety of low-carbohydrate-diets in Asian populations, whose carbohydrate intake is relatively high, is not known. Methods: We examined the association of low-carbohydrate-diets with CVD and total mortality using the National Integrated Project for Prospective Observation of Noncommunicable Disease and Its Trends in the Aged, (NIPPON DATA80) database with a 29-year follow-up. At the baseline in 1980, data were collected on study participants ages≥30 years from randomly selected areas in Japan. We calculated low-carbohydrate-diet scores based on the percentage of energy as carbohydrate, fat, and protein, estimated by 3-day weighed food records. We followed 9,200 participants (56% women, mean age 51 y). Results: During the follow-up, there were 1,171 CVD deaths (52% in women), and 3,443 total deaths (48% in women). The multivariate-adjusted hazard ratio (HR) for CVD mortality using the Cox model comparing highest versus lowest deciles for a low-carbohydrate-diet score was 0.59 (95% confidence interval [CI], 0.38-0.92, trend P=0.019) for women; 0.74 (95% CI: 0.55-0.99, trend P=0.033) for women and men combined; HR for total mortality was 0.73 (95% CI: 0.57-0.93, trend P=0.020) for women; 0.84 (95% CI: 0.72-0.99, trend P=0.030) for women and men combined. None of the associations in men alone were statistically significant. We did not note any differential effects between animal and plant based low-carbohydrate-diets. Conclusions: Moderate diets lower in carbohydrate and higher in protein and fat were significantly inversely associated with CVD and total mortality in women, and women and men combined.


BMJ ◽  
2018 ◽  
pp. k4583 ◽  
Author(s):  
Cara B Ebbeling ◽  
Henry A Feldman ◽  
Gloria L Klein ◽  
Julia M W Wong ◽  
Lisa Bielak ◽  
...  

AbstractObjectiveTo determine the effects of diets varying in carbohydrate to fat ratio on total energy expenditure.DesignRandomized trial.SettingMulticenter collaboration at US two sites, August 2014 to May 2017.Participants164 adults aged 18-65 years with a body mass index of 25 or more.InterventionsAfter 12% (within 2%) weight loss on a run-in diet, participants were randomly assigned to one of three test diets according to carbohydrate content (high, 60%, n=54; moderate, 40%, n=53; or low, 20%, n=57) for 20 weeks. Test diets were controlled for protein and were energy adjusted to maintain weight loss within 2 kg. To test for effect modification predicted by the carbohydrate-insulin model, the sample was divided into thirds of pre-weight loss insulin secretion (insulin concentration 30 minutes after oral glucose).Main outcome measuresThe primary outcome was total energy expenditure, measured with doubly labeled water, by intention-to-treat analysis. Per protocol analysis included participants who maintained target weight loss, potentially providing a more precise effect estimate. Secondary outcomes were resting energy expenditure, measures of physical activity, and levels of the metabolic hormones leptin and ghrelin.ResultsTotal energy expenditure differed by diet in the intention-to-treat analysis (n=162, P=0.002), with a linear trend of 52 kcal/d (95% confidence interval 23 to 82) for every 10% decrease in the contribution of carbohydrate to total energy intake (1 kcal=4.18 kJ=0.00418 MJ). Change in total energy expenditure was 91 kcal/d (95% confidence interval −29 to 210) greater in participants assigned to the moderate carbohydrate diet and 209 kcal/d (91 to 326) greater in those assigned to the low carbohydrate diet compared with the high carbohydrate diet. In the per protocol analysis (n=120, P<0.001), the respective differences were 131 kcal/d (−6 to 267) and 278 kcal/d (144 to 411). Among participants in the highest third of pre-weight loss insulin secretion, the difference between the low and high carbohydrate diet was 308 kcal/d in the intention-to-treat analysis and 478 kcal/d in the per protocol analysis (P<0.004). Ghrelin was significantly lower in participants assigned to the low carbohydrate diet compared with those assigned to the high carbohydrate diet (both analyses). Leptin was also significantly lower in participants assigned to the low carbohydrate diet (per protocol).ConclusionsConsistent with the carbohydrate-insulin model, lowering dietary carbohydrate increased energy expenditure during weight loss maintenance. This metabolic effect may improve the success of obesity treatment, especially among those with high insulin secretion.Trial registrationClinicalTrials.govNCT02068885.


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