Not All Overeating Is the Same: Why Eating Behavior Phenotypes Matter in GLP-1 Therapy

By Jean Cunningham, PharmD, BCPS, and Katherine Bowles, PharmD 

Key Clinical Takeaways 

• Patients with similar metabolic profiles can respond very differently to GLP-1 receptor agonists because the drivers of overeating are often different. 

• Eating behavior phenotyping may help clinicians identify which patients are most likely to achieve durable benefit from GLP-1 therapy. 

• Patients whose overeating is primarily driven by environmental food cues appear to experience the strongest and most sustained response. 

• Patients with prominent emotional eating may require behavioral intervention alongside pharmacotherapy to achieve durable outcomes. 

• The first several months of GLP-1 therapy may represent a critical “low-drive window” for implementing behavioral change. 

GLP-1 Therapy Is Changing Obesity Care, But Response Is Not Uniform 

GLP-1 receptor agonists (GLP-1 RAs) have fundamentally reshaped the treatment landscape for obesity and type 2 diabetes (T2D).^1,2,Yet clinicians see it every day: two patients with nearly identical A1c values, BMI, and medication histories can have dramatically different outcomes on the same GLP-1 therapy. 

One patient experiences profound appetite reduction, sustained weight loss, and improved glycemic control. Another initially responds, only to plateau or regain weight despite appropriate dosing and adherence. 

Why? 

Emerging evidence suggests the answer may lie less in metabolism alone and more in why patients eat. 

Eating behavior phenotypes, particularly emotional eating, external eating, and restrained eating, may offer a clinically useful framework for predicting response to GLP-1 therapy and identifying patients who need additional behavioral support.^2,3, 

For clinicians, this represents an important shift: obesity pharmacotherapy may be most effective when paired with behavioral precision medicine. 

The Three Eating Behavior Phenotypes 

The Dutch Eating Behaviour Questionnaire (DEBQ) categorizes overeating into three distinct behavioral patterns that are strongly associated with obesity and weight regain. Importantly, these patterns do not appear to respond equally to GLP-1 therapy. 

Emotional Eating 

Emotional eating occurs when food is used to regulate negative emotions such as stress, anxiety, sadness, loneliness, or frustration rather than physiologic hunger. 

For many patients, eating temporarily dampens emotional distress, creating a learned coping mechanism that persists even when appetite is pharmacologically suppressed. 

This distinction matters clinically.¹,² 

GLP-1 RAs effectively reduce hunger and food reward signaling, but they do not directly address emotional dysregulation, distress tolerance, or maladaptive coping patterns. As a result, emotional eaters may initially improve but struggle to sustain long-term behavioral change without additional psychological support. 

Emotional eating is highly prevalent in obesity care, affecting at least 40% of patients in clinical obesity populations and strongly overlapping with binge eating disorder.^2,4 

External Eating 

External eating is driven by environmental food cues rather than physiologic hunger. 

These patients are highly responsive to the sight, smell, availability, or anticipation of palatable food. Eating is often automatic, cue-triggered, and reward-driven. 

Mechanistically, this phenotype aligns closely with how GLP-1 RAs work. 

GLP-1 therapies modulate central reward circuitry and reduce the reinforcing value of highly palatable foods. The 2026 ADA Standards of Care acknowledge that incretin therapies influence appetite and reward pathways involved in overeating behavior.⁵ 

Among the three phenotypes, external eaters may therefore represent the most biologically aligned responders to GLP-1 therapy. 

Restrained Eating 

Restrained eating reflects deliberate attempts to control food intake for weight management. 

While restraint can support healthy behavior change, excessive restriction often creates a cycle of deprivation, disinhibition, binge eating, and weight regain. 

Interestingly, GLP-1 therapy may temporarily make restraint feel easier by reducing hunger and food preoccupation. However, evidence suggests this effect is often transient and may not translate into durable long-term behavioral change.⁶ 

What the Emerging Evidence Shows 

A 2025 multicenter prospective observational study from Japan evaluated 92 adults with T2D initiating liraglutide, dulaglutide, or semaglutide.⁶ Researchers assessed eating behavior phenotypes using the DEBQ at baseline, 3 months, and 12 months while tracking glycemic and weight-related outcomes. 

The findings were clinically revealing. 

External Eaters Showed the Strongest and Most Durable Response 

Patients with higher baseline external eating scores experienced greater weight reduction at 12 months and showed a trend toward improved glycemic outcomes. 

Notably, reductions in external eating behaviors persisted throughout the study period, suggesting GLP-1 therapy may directly modify the reward-driven eating patterns underlying this phenotype.⁶

In practical terms, these patients appeared to experience not only metabolic improvement, but also sustained behavioral improvement. 

Emotional Eaters Improved Early, Then Drifted Back to Baseline 

Patients with emotional eating demonstrated a very different trajectory. 

Although emotional eating scores initially improved during the first months of therapy, these gains largely disappeared by 12 months.⁶ 

This pattern supports an important clinical insight: reducing appetite alone may not be sufficient when eating behavior is primarily emotion-driven. 

For these patients, pharmacotherapy may reduce the urge to eat, but it does not necessarily replace the underlying coping mechanism. 

Restrained Eating Was Not Predictive of Outcomes 

Restrained eating scores also improved transiently early in treatment but returned toward baseline over time. 

No significant association was observed between restrained eating and long-term clinical outcomes. 

The “Low-Drive Window”: An Opportunity Clinicians May Be Missing 

One of the most compelling concepts emerging from recent literature is the idea of a GLP-1-induced “low-drive window”.² 

During the early months of therapy, appetite, food reward, and food preoccupation are often maximally suppressed. For many patients, this creates a temporary period of cognitive and behavioral quiet around eating. 

This window may represent the ideal time to introduce behavioral interventions. 

Patients who previously felt overwhelmed by cravings or compulsive eating may, for the first time in years, have enough psychological space to build new coping strategies, emotional regulation skills, and eating patterns. 

From a clinical operations perspective, timing matters. 

Based on this proposed framework, behavioral referrals initiated six to twelve months after pharmacotherapy may miss the period when patients are most receptive and neurologically primed for change.

Why Behavioral Support Matters for Emotional Eaters 

The evidence increasingly suggests that emotional eaters benefit most from a combined treatment model rather than pharmacotherapy alone.⁴ 

Cognitive Behavioral Therapy (CBT) 

CBT currently has the strongest evidence base for reducing emotional eating.^7,8 

Meta-analyses demonstrate meaningful reductions in emotional eating behaviors, particularly when interventions target maladaptive beliefs, emotional triggers, goal setting, and self-monitoring. 

Importantly, CBT helps patients build alternative coping strategies rather than relying on food for emotional regulation. 

For clinicians, this distinction is critical: GLP-1 therapy can reduce appetite, but CBT addresses the reason patients turn to food in the first place. 

Mindfulness-Based Interventions 

Mindfulness approaches focus on restoring interoceptive awareness and helping patients recognize hunger, satiety, cravings, and emotional triggers more accurately. 

Randomized trials show meaningful reductions in emotional eating even when weight loss itself is modest.⁹,¹⁰ 

These interventions may be particularly useful for patients whose eating patterns are automatic, stress-reactive, or disconnected from physiologic hunger cues. 

Acceptance and Commitment Therapy (ACT) 

ACT helps patients tolerate difficult emotions without attempting to suppress or escape them through eating. 

Rather than fighting cravings or emotions directly, patients learn psychological flexibility and values-based decision-making. 

Emerging evidence suggests ACT may improve emotional eating behaviors, particularly in patients with chronic shame, repeated dieting failure, or emotional avoidance.¹¹,¹² 

Dialectical Behavior Therapy (DBT) 

DBT-based approaches target emotion regulation, distress tolerance, and impulsive behavior.¹³,¹⁴ 

These strategies may be especially valuable for patients whose overeating occurs during periods of intense emotional dysregulation. 

Importantly, DBT recognizes that emotional eating is not simply a failure of willpower. In many patients, it represents an underdeveloped emotional regulation system. 

A Practical Framework for Clinicians 

1. Assess Eating Behavior Before Starting Therapy

Incorporating brief behavioral screening tools such as the DEBQ or Binge Eating Scale before initiating GLP-1 therapy may help clinicians identify likely responders and recognize patients who need additional support.^3,6 

2. Identify Patients Most Likely to Respond 

Patients with strong external eating patterns may represent ideal pharmacotherapy candidates because their overeating behaviors align closely with GLP-1 mechanisms of action.⁶ 

3. Escalate Support Early for Emotional Eaters

Patients with significant emotional eating may benefit from early referral to behavioral health, obesity psychology, or structured weight management programs. 

Waiting until treatment failure occurs may delay meaningful intervention. 

4. Use the Early Treatment Window Strategically

The first months of therapy may be the optimal time to establish new behavioral routines while food noise and reward drive are suppressed. 

5. Plan Beyond the Prescription

Weight regain following GLP-1 discontinuation is common, particularly in patients whose underlying emotional eating patterns remain untreated.² 

Long-term success may depend as much on behavioral adaptation as pharmacotherapy persistence. 

The Bigger Clinical Message 

GLP-1 receptor agonists are powerful tools, but obesity is not simply a disease of appetite. 

Some patients eat because food is highly rewarding. Some eat because food is emotionally regulating. Others eat within cycles of restriction and disinhibition. 

These distinctions matter. 

As obesity medicine becomes increasingly personalized, eating behavior phenotyping may help clinicians move beyond a one-size-fits-all prescribing model toward a more integrated and durable approach to care. 

The future of obesity treatment may not be choosing between pharmacotherapy or behavioral intervention.^2,6 

It may be learning which patients need both from the very beginning.