Reconceptualization of Eating Addiction and Obesity as Displacement Behavior and a Possible Treatment

Purpose: Displacement behavior is a bio-behavioral mechanism that allows an animal to deal with situations that cannot readily be faced nor avoided, or that are thwarting. It may explain compulsive overeating (eating addiction). Resembling addiction, displacement behavior is irrepressible behavior that is contextually inappropriate, e.g., sleeping or feeding when threatened by a predator, or binge eating in response to a work altercation. It is thought to be due to rechanneling of overflow brain energy to another drive (e.g., feeding drive) when two drives, e.g., fight or flight, equally oppose each other. Moving the opposing drives out of equilibrium, by resolving the person’s underlying problem/stressful situations, theoretically should mitigate the displacement mechanism and addictive overeating. Methods: We developed a mobile phone intervention targeting addictive overeating, including a displacement mechanism component. A displacement use subgroup (N=37) ages 14-24 with obesity (mean BMI= 38.1) identified life situations they could neither face nor avoid, or that were thwarting them, and developed action plans to address each situation. Feasibility and acceptability were evaluated. Results: Participants found the displacement component to be understandable and user-friendly. The majority (26/37 – 70%) used the core “Dread List” feature to input 90 individual dreaded/problem situations fueling displacement-based overeating, coupled with action plans to address each problem. Conclusion: The displacement mechanism may be a useful basis for treatment of eating addiction and obesity, and may provide individuals with hope that they can curb their addiction without relying on willpower to not overeat. A randomized trial evaluating the displacement intervention is planned.

Glycoside hydrolase family 5: structural snapshots highlighting the involvement of two conserved residues in catalysis

The ability of retaining glycoside hydrolases (GHs) to transglycosylate is inherent to the double-displacement mechanism. Studying reaction intermediates, such as the glycosyl-enzyme intermediate (GEI) and the Michaelis complex, could provide valuable information to better understand the molecular factors governing the catalytic mechanism. Here, the GEI structure of RBcel1, an endo-1,4-β-glucanase of the GH5 family endowed with transglycosylase activity, is reported. It is the first structure of a GH5 enzyme covalently bound to a natural oligosaccharide with the two catalytic glutamate residues present. The structure of the variant RBcel1_E135A in complex with cellotriose is also reported, allowing a description of the entire binding cleft of RBcel1. Taken together, the structures deliver different snapshots of the double-displacement mechanism. The structural analysis revealed a significant movement of the nucleophilic glutamate residue during the reaction. Enzymatic assays indicated that, as expected, the acid/base glutamate residue is crucial for the glycosylation step and partly contributes to deglycosylation. Moreover, a conserved tyrosine residue in the −1 subsite, Tyr201, plays a determinant role in both the glycosylation and deglycosylation steps, since the GEI was trapped in the RBcel1_Y201F variant. The approach used to obtain the GEI presented here could easily be transposed to other retaining GHs in clan GH-A.

Characterization of the Dynamic Imbibition Displacement Mechanism in Tight Sandstone Reservoirs Using the NMR Technique

An experimental technique is developed to investigate the dynamic imbibition displacement mechanism in tight sandstone formations of the Yanchang group of the Ordos basin. By combining the dynamic imbibition core flooding experiments and NMR technique, the effects of the injection volume and rate on displacement efficiency are investigated. Moreover, the displacement efficiency of dynamic imbibition is compared with that of static imbibition. This study gains insights into the micromechanisms of dynamic imbibition in tight sandstone formations. It is found that the relative displacement efficiency of dynamic imbibition increases with the increase of injection volume. But the increment amplitude decreases with the increase of injection volume. With the same injection volume, the core displacement efficiency of dynamic imbibition with high permeability is obviously improved. However, the core displacement efficiency decreases rapidly with the increase of injection volume. Optimal injection volumes are recommended for tight sandstone formations with different permeabilities. With the increase of the displacement rate, the core displacement efficiency of dynamic imbibition shows a trend of first rising and then declining. There exists an optimal displacement rate in dynamic imbibition displacement, and the optimal displacement rate almost linearly increases with the increase of core permeability. The static imbibition displacement efficiency increases with the increase of soaking time, but the increment amplitude slows down obviously. The displacement efficiency of static imbibition in small pores is higher than that of dynamic imbibition. The displacement efficiency of dynamic imbibition in large pores or microcracks is significantly higher than that of static imbibition. This study provides theoretical support for the optimization and improvement of the waterflooding recovery process in tight sandstone reservoirs.

332 What’s causing obesity in pets and what can we do about it?

The majority of dogs (56%) and cats (60%) are now overweight or obese. A novel theory posits that obesity in pets is due to “treats” and excessive meal amounts given by the “pet-parent” to obtain affection from the pet, which enables “‘eating addiction” in the pet and results in pet-parent “co-dependence.” The pet-parent may even become hostage to the treats/food to avoid the ire of the pet. Eating addiction in the pet appears related to stress/conflict, involving the displacement mechanism, which is a bio-behavioral mechanism in the brains of all animals, even fruit flies. It allows the animal to deal with situations that cannot readily be faced or avoided or are thwarting, such as social isolation. Displacement behavior is out-of-context, irrepressible behavior, e.g. an animal in the wild who sleeps or feeds when threatened by a predator. It is thought due to re-channeling of overflow brain energy to another drive (e.g. feeding drive) when two drives, e.g. fight or flight, equally oppose each other. Moving the opposing drives out of equilibrium, by resolving the animal’s stressful life situations, theoretically halts the displacement mechanism and addictive behavior, e.g. overeating/obesity. Similarly, dealing with the pet-parent’s stressful life situations curtails displacement regarding overfeeding the pet. Treatment for each contribution to companion animal obesity will be presented: Pet-parent seeking affection from the pet by giving food treats, which induces and subsequently triggers displacement overeating in the pet -- > Treatment is pet-parent withdrawal/abstinence from treat-giving. Displacement of pet-parent’s stressful life situations by feeding the pet. The received affection induces and subsequently triggers further treat-giving by the pet-parent. -- > Treatment is developing an action plan for each of the pet-parent’s stressful life situations. Begging, annoyance, aggression, and hostage state of the pet. -- > Treatment is “tough love” by the pet-parent.