Research Category: Weight Management

French-fried potatoes consumption and energy balance: a randomized controlled trial


Epidemiologic observations suggest increased potato consumption correlates with weight gain, adiposity, and diabetes risk, while nut consumption is associated with weight control and metabolic health. Randomized controlled trial (RCT) data indicate humans respond to changes in energy intake in single dietary components and compensate for extra energy consumed.

Effect of White Potatoes on Subjective Appetite, Food Intake, and Glycemic Response in Healthy Older Adults

The objective of this study was to determine the effect of white potato cooking methods on subjective appetite, short-term food intake (FI), and glycemic response in healthy older adults. Using a within-subject, repeated-measures design, 20 participants (age: 70.4 ± 0.6 y) completed, in random order, five treatment conditions: three potato treatments (baked potatoes, mashed potatoes, and French fries), an isocaloric control treatment (white bread), or a fasting condition (meal skipping). Subjective appetite and glycemic response were measured for 120 min using visual analogue scales and capillary blood samples, respectively. Lunch FI was measured with an ad libitum pizza meal at 120 min. Change from baseline subjective appetite (p < 0.001) and lunch FI (p < 0.001) were lower after all test treatments compared with meal skipping (p < 0.001), but did not differ among test treatments. Cumulative FI (test treatment + lunch FI) did not differ among treatment conditions. Blood glucose concentrations were higher after all test treatments compared with meal skipping (p < 0.001), but were not different from each other. In healthy older adults, white potatoes suppressed subjective appetite and lunch FI compared with meal skipping, suggesting white potatoes do not bypass regulatory control mechanisms of FI.

Potato Consumption and Risk of Cardio-Metabolic Diseases: Evidence Mapping of Observational Studies

Background: Recent systematic review of clinical trials concluded that there was no convincing evidence to suggest an association between potatoes and risk of cardio-metabolic diseases. Objective: Summarize observational study data related to potato intake and cardio-metabolic health outcomes in adults using evidence mapping to assess the need for a future systematic review. Methods: We searched MEDLINE®, Commonwealth Agricultural Bureau, and bibliographies for eligible observational studies published between 1946 and July 2020. Included studies evaluated potato intake in any form or as part of a dietary pattern with risk for cardio-metabolic diseases. Outcomes of interest included cardiovascular disease (CVD), cerebrovascular diseases, diabetes, hypertension, blood lipids, and body composition. Results: Of 121 eligible studies, 51 reported two different methods to quantify potato intake (30 studies quantified intake as either grams or serving; 20 studies reported times per week; one reported both methods) and 70 reported potato as part of a dietary pattern and compared higher vs. lower intake, linear change, or difference in potato intake among cases and controls. Studies that quantified potato intake as either grams or serving reported the following outcomes: diabetes (8 studies); cerebrovascular stroke (6 studies); five studies each for CVD, systolic and diastolic blood pressure, and hypertension; three studies each for body mass index, body weight, CVD mortality; two studies for myocardial infarction; and one study each for blood glucose, HOMA-IR, and blood lipids. Higher potato intake was associated with an increased risk for blood pressure and body weight, and the results of all other outcomes observed no association. Potato consumption as part of dietary pattern studies reported a negative association between fried form of potato and all or most cardio-metabolic risk factors and diseases. Conclusion: Evidence mapping found sufficient data on the association between potato intake and cardio-metabolic disease risk factors to warrant for a systematic review/meta-analysis of observational studies.

Daily Intake of Non-Fried Potato Does Not Affect Markers of Glycemia and is Associated with Better Diet Quality Compared to Refined Grains: A Randomized, Crossover Study in Healthy Adults

Epidemiologic studies suggest that consumption of potatoes is associated with increased risk of cardiometabolic diseases. However, few clinical trials have empirically tested these observational findings. The aim of this single-blind, randomized, crossover study was to evaluate the effect of daily potato consumption, compared to refined grains, on risk factors for cardiometabolic diseases. It was hypothesized that no difference in cardiometabolic endpoints would be detected between conditions, but diet quality would improve with potato consumption. Healthy participants on self-selected diets received one potato-based side dish or one refined grain-based side dish daily, for four weeks, separated by a minimum two-week break. Dishes were isocaloric, carbohydrate-matched, and prepared without excess saturated fat or sodium. Participants were instructed to consume the side-dish with a meal in place of carbohydrates habitually consumed. Lipids/lipoproteins, markers of glycemic control, blood pressure (BP), weight and pulse wave velocity (PWV) were measured at baseline and condition endpoints. Diet quality was calculated, based on 24-hour recalls, using the Healthy Eating Index (HEI)-2015. Fifty adults (female n=34; age: 40±13; BMI: 24.5±3.6 kg/m2) completed this study. No between-condition differences were detected for fasting plasma glucose (-0.97; mg/dL, 95% CI: -2.3, 0.35; p=0.15), the primary outcome, or any other outcomes. Compared with refined grains, the HEI-2015 score (3.5, 95%CI: 0.6, 6.4 p=0.01), potassium (547 mg, 95%CI: 331, 764, p<0.001) and fiber (2.4 g, 95% CI: 0.6, 4.2, p=0.01) were higher following the potato condition. Consuming non-fried potatoes resulted in higher diet quality, potassium and fiber intake, without adversely affecting cardiometabolic risk.

Effects of White Potatoes Consumed With Eggs on Satiety, Food Intake, and Glycemic Response in Children and Adolescents

Objective: Short-term studies in adults have shown that white potatoes increase satiety and suppress food intake (FI) compared with several other carbohydrate-containing foods; however, studies are limited in children. The objective was to compare the effects of white potatoes in mixed meals on satiety, FI, and glycemic response in 9-14-year-old children and adolescents. Methods: Using a within-subject, repeated-measures design, 21 children completed five counter-balanced test sessions. After an overnight fast, children consumed one of four isocaloric treatment meals (450 kcal) of French fries, mashed potatoes, or white beans served with a fixed portion of egg omelet (30 g of protein), a control meal with cereal, milk, and bread, or continued to fast (i.e., meal skipping). Subjective appetite was measured using visual analogue scales. FI at an ad libitum pizza meal at 180 min and rest of day diet record were used to measure lunch FI and rest of day energy intake, respectively. Total daily energy intake was calculated by adding the energy intake from the treatment meal, the ad libitum pizza lunch, and rest of day food record. Capillary blood samples were collected to assess glycemic response over 180 min. Results: Change from baseline subjective average appetite scores were lower after mashed potatoes compared with all other treatment conditions (p < 0.001), and higher after French fries compared with white beans (p = 0.04). Lunch FI (kcal) was significantly lower (p < 0.001) after French fries (1010±73) and mashed potatoes (1039±74) compared with the control meal (1257±92) and meal skipping (1235±74). Total daily energy intake (kcal) was lower after French fries compared with the control meal (2228±141 vs. 2624±137; p = 0.04). Change from baseline blood glucose was lower after white beans and French fries compared with mashed potatoes (p < 0.05) and the control meal (p < 0.001). Conclusion: In conclusion, white potatoes with eggs increased satiety, decreased short-term FI, and resulted in similar energy intakes compared with meal skipping.

White Vegetables: Glycemia and Satiety

The objective of this review is to discuss the effect of white vegetable consumption on glycemia, satiety, and food intake. White vegetables is a term used to refer to vegetables that are white or near white in color and include potatoes, cauliflowers, turnips, onions, parsnips, white corn, kohlrabi, and mushrooms (technically fungi but generally considered a vegetable). They vary greatly in their contribution to the energy and nutrient content of the diet and glycemia and satiety. As with other foods, the glycemic effect of many white vegetables has been measured. The results illustrate that interpretation of the semiquantitative comparative ratings of white vegetables as derived by the glycemic index must be context dependent. As illustrated by using the potato as an example, the glycemic index of white vegetables can be misleading if not interpreted in the context of the overall contribution that the white vegetable makes to the carbohydrate and nutrient composition of the diet and their functionality in satiety and metabolic control within usual meals. It is concluded that application of the glycemic index in isolation to judge the role of white vegetables in the diet and, specifically in the case of potato as consumed in ad libitum meals, has led to premature and possibly counterproductive dietary guidance.