General and persistent effects of high-intensity sweeteners on body weight gain and caloric compensation in rats

Abstract

In an earlier work (S. E. Swithers & T. L. Davidson, 2008), rats provided with a fixed amount of a yogurt diet mixed with saccharin gained more weight and showed impaired caloric compensation relative to rats given the same amount of yogurt mixed with glucose. The present 4 experiments examined the generality of these findings and demonstrated that increased body weight gain was also demonstrated when animals consumed a yogurt diet sweetened with an alternative high-intensity sweetener (acesulfame potassium; AceK) as well as in animals given a saccharin-sweetened base diet (refried beans) that was calorically similar but nutritionally distinct from low-fat yogurt. These studies also extended earlier findings by showing that body weight differences persist after saccharin-sweetened diets are discontinued and following a shift to a diet sweetened with glucose. In addition, rats first exposed to a diet sweetened with glucose still gain additional weight when subsequently exposed to a saccharin-sweetened diet. The results of these experiments add support to the hypothesis that exposure to weak or nonpredictive relationships between sweet tastes and caloric consequences may lead to positive energy balance.

Figure 1

Body weight gain is significantly higher in male rats given either 23-hr access or 1-hr access to yogurt diets sweetened with Saccharin or AceK compared with rats given yogurt diets sweetened with glucose. Body weight was recorded daily - data points are omitted for clarity. * p < 0.01 compared with Saccharin and AceK animals given the same duration (1 or 23 hr) of access to yogurt

Figure 2

Body weight gain was significantly greater during presentation of saccharin-sweetened yogurt compared with glucose-sweetened yogurt (A). Following termination of yogurt presentation (B), no differences in body weight gain were observed. * p < 0.01 compared with Glucose

Figure 3

Body weight gain (A) and body weight (C) during Phase 1 of exposure to yogurt or bean diets sweetened with Saccharin (Circles) or Glucose (Squares). During phase 2, base diets were switched and body weight gain (B) and body weight (D) were affected by the sweeteners employed. In all panels, sweetener groups are collapsed across both beans and yogurt base diets. * p < 0.05 compared with Glucose-Saccharin, Saccharin-Glucose and Saccharin-Saccharin # p < 0.05 compared with Glucose-Saccharin and Saccharin-Saccharin @ p < 0.05 compared with Glucose-Saccharin

Figure 4

Chow intake following a novel sweetened diet was affected by the sweetener provided during phase 2 when sweetened beans were provided during phase 1 and sweetened yogurt was provided during phase 2. Animals given saccharin-sweetened yogurt during phase 2 of training showed significantly weaker compensation for calories provided in a novel, sweet-tasting premeal (A and B; closed symbols represent intake on premeal days, open symbols represent intake on no premeal days) compared with animals given glucose-sweetened yogurt during phase 2 (C and D; symbols as in A and B).

Figure 5

Chow intake following a novel sweetened diet was not affected by the sweetener provided during phase 2 in when sweetened yogurt was provided during phase 1 and sweetened beans were provided during phase 2. Both animals given saccharin-sweetened beans during phase 2 of training (A and B; closed symbols represent intake on premeal days, open symbols represent intake on no premeal days) and animals given glucose-sweetened beans during phase 2 (C and D; symbols as in A and B) showed greater intake on premeal days compared with no premeal days.