Eating Behaviours in Frontotemporal Dementia: Impulsivity, Hyperphagia and Safety

Frontotemporal dementia (FTD) — particularly the behavioural variant (bvFTD) — is associated with one of the most distinctive and clinically challenging eating disorder profiles in all of dementia care. Unlike Alzheimer’s disease, where dysphagia tends to emerge late in the course from progressive motor and cognitive decline, FTD disrupts eating through behavioural disinhibition early in the disease — creating aspiration risk through entirely different mechanisms.

Understanding FTD eating is important for clinicians, caregivers, and care home staff, because applying generic dementia dysphagia protocols to FTD patients often misses the real risks.

This article follows ASHA Practice Portal guidance on adult dysphagia and NICE CG162.

Pathophysiology: Why FTD Changes Eating

bvFTD results from progressive degeneration of the frontal and anterior temporal lobes, particularly the orbitofrontal cortex, anterior cingulate cortex and the right hemisphere structures involved in self-monitoring, inhibition and social cognition.

These circuits normally regulate:

• Impulse control at mealtimes — slowing eating pace, chewing before swallowing
• Satiety recognition — stopping when full
• Social eating norms — not taking others’ food, appropriate portion sizes
• Sensory-specific satiety — normal food preference variation
• Voluntary cough and airway protection — cortical oversight of protective reflex responses

Bilateral frontal degeneration releases all of these from inhibitory control, producing the characteristic FTD eating disorder.

The Spectrum of FTD Eating Difficulties

Hyperphagia

Increased food intake — sometimes dramatically so — is present in 60–80% of bvFTD patients. Patients may eat several times their previous intake, seek food continuously throughout the day, eat from others’ plates, and become agitated when food is withheld. The neurological basis is degeneration of the orbitofrontal cortex and hypothalamic control circuits.

Hyperphagia creates an aspiration risk because patients may eat so quickly, or consume such large quantities, that bolus size and oral preparation time become unsafe. Large bolus stuffing into the mouth is a direct aspiration precipitant.

Changed Food Preferences

A hallmark of bvFTD is a specific shift toward sweet and high-carbohydrate foods. Patients who previously ate a balanced diet may insist exclusively on biscuits, sweets, fizzy drinks and desserts. This reflects altered insular-temporal gustatory processing and loss of dietary self-regulation.

The clinical implication is twofold: nutritional imbalance (excessive calories without protein or micronutrients) and aspiration risk from the textures often preferred (thin liquids, crumbly biscuits, mixed consistencies).

Oral Exploration of Non-Food Items

Some bvFTD patients develop hyperorality — placing non-food objects in the mouth. This represents a severe form of environmental dependency and disinhibition. In residential care, this creates both aspiration and choking hazards from objects.

Impulsive Eating Pace

Without frontal inhibition of eating pace, FTD patients often eat very rapidly, with inadequate time for oral preparation of each bolus. They may swallow insufficiently chewed food, or not pause between mouthfuls, dramatically increasing aspiration risk with solid food.

Late-Stage Swallowing Dysfunction

In later stages of FTD, as atrophy extends into motor cortex and brainstem-projecting circuits, true neurogenic dysphagia develops — with delayed pharyngeal swallow initiation, reduced pharyngeal constrictor function, and aspiration similar to that seen in Alzheimer’s late-stage dementia.

Assessment Challenges

Standard SLT dysphagia assessment assumes patient cooperation with task completion (holding boluses, swallowing on command, following postural instructions). FTD patients present multiple obstacles:

• Impulsive eating during assessment may mean the patient does not wait for instruction
• Insight impairment means self-report of symptoms is unreliable
• Disinhibited behaviour during FEES or VFSS may prevent standardised testing
• Fluctuating cooperation depending on the assessment environment

A naturalistic, ecological assessment during an actual meal — observed by an SLT or trained caregiver using a structured observation tool — often yields more clinically useful information than a standardised bolus assessment for this population. This approach has been supported by the HKU Swallowing Research Lab (Prof. Karen Chan) as an adjunct to formal instrumental assessment in behaviourally complex dementia patients.

Management Strategies

Pacing and Environmental Control

• Small, pre-portioned servings to control bolus size
• Remove food items when the patient has finished their portion to prevent continuous foraging
• One food item on the plate at a time to reduce stuffing
• Verbal or physical cues to slow eating pace (“one bite at a time”)
• Distraction-free eating environment to reduce impulsive, rapid intake

Diet Modification

Texture modification using the IDDSI framework may be needed in late-stage disease or when specific aspiration risks are identified. In early and middle stages, the priority is usually behavioural management of eating pace rather than blanket texture restriction — over-restricting texture in bvFTD can increase agitation and food refusal.

Supervision During Meals

One-to-one or supervised eating (small group with trained staff) is often necessary to prevent bolus stuffing, food stealing and ingestion of non-food items. In Hong Kong residential care homes, this level of supervision requires specific care planning documentation and resourcing.

Nutritional Monitoring

Hyperphagia causes obesity and metabolic complications. Paradoxically, some FTD patients who shift entirely to sweet foods develop protein-energy malnutrition despite high caloric intake. Regular dietitian review and MNA-SF screening are recommended.

When to Refer

Any FTD patient with rapid weight gain or weight loss, recurrent chest infections, or behavioural eating patterns creating safety concerns should be referred for SLT assessment and dietitian review. See When to Refer to a Speech and Language Therapist.

References

1. American Speech-Language-Hearing Association. Adult Dysphagia Practice Portal. https://www.asha.org/practice-portal/clinical-topics/adult-dysphagia/
2. National Institute for Health and Care Excellence. Stroke Rehabilitation in Adults (CG162). https://www.nice.org.uk/guidance/cg162
3. IDDSI. The IDDSI Framework. https://www.iddsi.org/framework
4. Logemann JA, et al. (2015). Disorders of deglutition. Handbook of Clinical Neurology, 129, 465–487. PMID: 26315994