Consumption of the slow digesting starch waxy maize leads to blunted and sustained carbohydrate utilization but does not influence energy expenditure or appetite

Abstract

Background: The postprandial metabolic and appetitive responses of waxy maize, a slow‐digesting carbohydrate (CHO), are undocumented in humans and were examined in this study.Methods: 12 young, physically fit men and women (age: 23 ± 1 y; BMI: 22.2 ± 0.7 kg/m2; physical activity: 556 ± 120 min/wk) consumed, on separate testing days, 50 g of available CHO as either fast‐digesting maltodextrin (M) or waxy‐maize starch (WM). Plasma glucose and insulin concentrations, whole body energy expenditure and appetite (hunger, fullness, and desire to eat) were measured over 4 h.Results: Compared to M, WM led to lower postprandial glucose (1082 ± 151 vs. 2186 ± 262 mg/dL•240 min; p<0.001) and insulin (833 ±164 vs. 1628 ± 165 uU/mL•240 min; p<0.005) area under the curve during the 4 h period. These differences were driven by the blunted glucose response during the first hour (p<0.001) and the blunted insulin response during the first two hours (p<0.005) in WM. CHO utilization was lower after 1 h but higher after 4 h following WM vs. M. Composite CHO utilization over the entire 4 h period was not different between WM and M. No differences in energy expenditure or appetite were observed between WM vs. M.Conclusion: These results support that waxy maize provides sustained glucose availability in young, physically fit adults.Support: US Army, Natick Soldier RDECOM, Combat Feeding Directorate; Ingestive Behavior Res. Ctr., Purdue University

Influence of modified starches on mental performance and physical activity following an exhaustive bout of exercise

“…We did see changes due to consuming HMS before and during exercise that influenced the physiological response to prolonged exercise; however, these changes did not differentiate serum glucose levels between HMS and MAL as expected. Typically, the stabilization would be due in part to the extensive amylopectin branching found in HMS structures (Sands et al., 2008 ). Complex amylopectin structures hinder the function of enzymes responsible for the breakdown of carbohydrates (Murray & Rosenbloom, 2018 ).…”

“…Previous studies have indicated that superstarches are more effective in treating and preventing hypoglycemia and may aid in sparing CHO stores by promoting the utilization of fats for energy during prolonged exercise (Baur et al., 2016 ; Roberts et al., 2011 ). It is expected that athletes will maintain more stable blood glucose when HMS is consumed compared to maltodextrins (MALs) due to subdued insulin response (Sands et al., 2008 ). Studies have also noted that ingesting a HMS before and during endurance cycling enhances fat oxidation and reduces CHO oxidation during exercise (Baur et al., 2016 ; Sands et al., 2008 ).…”

“…It is expected that athletes will maintain more stable blood glucose when HMS is consumed compared to maltodextrins (MALs) due to subdued insulin response (Sands et al., 2008 ). Studies have also noted that ingesting a HMS before and during endurance cycling enhances fat oxidation and reduces CHO oxidation during exercise (Baur et al., 2016 ; Sands et al., 2008 ). Due to the sensitivity of lipolysis, small decreases in insulin are associated with increases in fat oxidation (Roberts et al., 2011 ).…”

“…These forms allow individuals to easily ingest fuel before, during, and after bouts of exercise. Carbohydrates can be divided into the following three categories: rapid, resistant, and slow, based on digestibility (Sands et al., 2008 ). As the term implies, rapid‐digesting starches break down quickly, usually within 20 min of consumption.…”

“…Resistant starches are the by‐products not absorbed by the small intestine after digestion. Slow‐digesting starches are digested in vitro between 20 and 120 min after ingestion (Sands et al., 2008 ).…”