Physical Activity, Energy Intake, and Obesity: The Links Between Exercise and Appetite

Abstract

Overweight and obesity are often theorized using the energy balance equation. When energy intake (EI) is greater than energy expended this creates a positive energy balance and leads to weight gain, conversely when energy expenditure (EE) exceeds EI this creates a negative energy balance and weight loss. Physiologists have been examining the relationship between EE and EI since the 1950s. Total daily EE is comprised of two main components; resting metabolic rate (RMR) and physical activity (PA). This review will examine and report the relationships between both major components of EE and EI, and therefore the impact of PA on body weight. The relationship between energy expended through PA and EI appears to be weak, especially within one day and over longer periods in overweight and obese adults. However, recent data have demonstrated a strong relationship between RMR, hunger and food intake. The differences observed in the relationships between PA EE and EI and metabolic EE and EI are not surprising. EE from PA is highly variable and episodic whereas EE from RMR is very stable and tonic. These new data provide evidence for a fundamental link between EE and EI.

Differential relationship between physical activity and intake of added sugar and nutrient-dense foods: A cross-sectional analysis

“…While the beneficial effects of physical activity (PA) on many obesity-related diseases such as diabetes, cardiovascular disease, and certain cancers are well established (3)(4)(5), the effectiveness of PA on weight status, and particularly its capacity to promote weight loss, remains under debate (6). Energy balance, and ultimately weight loss and weight gain, is a direct result of dietary energy intake and energy expenditure (7,8). As PA represents the only component of energy expenditure that is driven directly by behavior and therefore is its most variable contributor (9), it is critical to understand the impact of PA on food intake and particularly whether increased PA invokes a compensatory effect on food intake which could negate beneficial effects of PA on weight status (10).…”

Does Habitual Physical Activity Increase the Sensitivity of the Appetite Control System? A Systematic Review

“…There has been increasing interest in the relationship between physical activity and appetite control, as both play an integral part in energy balance (e.g. [3–7]). Regular physical activity and exercise training are associated with several physiological adaptations, such as improved insulin sensitivity [8], leptin sensitivity [9, 10], blood pressure [11], blood lipids [12], substrate metabolism [13] and body composition [14], some of which have been proposed as mechanisms involved in eating behaviour [15, 16].…”

Effects of Exercise on Appetite-Regulating Hormones, Perceived Hunger, and Energy Intake: A Narrative Overview

“…However, increasing exercise and therefore, energy expenditure, does not always result in desired weight loss. In a recent review, Caudwell, Gibbons, Finlayson, Naslund, and Blundell (2013) reported that, although the research predominantly shows an acute bout of exercise does not create an increase in hunger, desire to eat, or energy intake, when exercise is extended over a few days and caloric intake is monitored for a longer period, partial compensation for increased energy expenditure can occur. In these cases, even though individuals are increasing physical activity, they are subsequently increasing #0# caloric intake thereby undermining their own weight loss efforts.…”

“…In these cases, even though individuals are increasing physical activity, they are subsequently increasing #0# caloric intake thereby undermining their own weight loss efforts. High-intensity exercise is correlated with a transient reduction in hunger that may be due to a temporary decrease in the active component of the appetitestimulating hormone ghrelin (Caudwell et al, 2013). The appetite-regulating hormones acylated ghrelin, leptin, GLP-1, and PYY 3-36 are recognized to be a major influence on energy homeostasis (Klok, Jakobsdottir, Drent, 2007).…”

“…Ghrelin has an appetite stimulating effect, whereas increases in leptin, GLP-1, and PYY 3-36 tend to have appetite-suppressing effects, except in cases of leptin resistance in which increased levels of leptin do not correlate with appetite-suppression. These hormones respond differently to varying exercise modes (cardiovascular and resistance training), intensities, and duration (Caudwell et al, 2013;Klok et al, 2007). The purpose of this narrative review is to examine and describe the current evidence on the effect different exercise forms (cardiovascular and resistance training), intensities, and duration of exercise has on appetite-regulating hormones (leptin, acylated ghrelin, GLP-1, and PYY 3-36 ), perceptions of hunger, and energy intake in overweight/obese, and normal weight populations.…”