The schedule, not the sugar: intermittent versus continuous access

In the animal model, what produces binge-like, escalating sugar intake is not sugar as such but intermittent access — a daily cycle of deprivation and renewed access. Animals on that schedule escalate their first-hour intake across days; animals with the same sugar available continuously do not. Move the day marker and compare the two schedules: intermittent(d) = 20 + 40(1 − e−0.25d) and continuous(d) = 25 + 5(1 − e−0.25d).

Day on the schedule (d)10
010203040506070first-hour intakedays on schedule (d)intermittentcontinuous
At day 10, intermittent-access intake is 56.7 and continuous-access intake is 29.6 — a gap of 27.1. The intermittent schedule has driven intake 1.9× the continuous level. This is the central caution of the animal evidence: it isolates the pattern of access, not sugar itself, as the addictive-like variable — a point the human literature still debates.

Why some foods rate as addictive

When people rate foods for addictive-like eating, the ratings rise with how heavily the food is processed and with its fat and rapidly-available carbohydrate — not with any single nutrient alone. Switch the horizontal axis between the three candidate predictors and watch how tightly each one tracks the addictive rating. Processing level orders the seven foods most cleanly; glycemic load alone misplaces soda.

0.000.000.250.250.500.500.750.751.001.00addictive rating →processing level →ChocolatePizzaFrench friesSodaBrown riceAppleCucumber
Across the seven foods, processing level correlates with the addictive rating at r = 0.83. Processing level gives the tightest ordering — the red (highly processed) foods cluster at high addictive ratings and the green (whole) foods at low ones. This is Schulte and colleagues’ central claim: the degree of processing, more than any natural property, marks a food as addictive-like.

From symptom criteria to a severity band

The Yale Food Addiction Scale counts the same eleven criteria the DSM-5 uses for a substance-use disorder, then applies a gate: a diagnosis needs at least two criteria and clinically significant distress or impairment. Severity follows the count — two to three mild, four to five moderate, six or more severe. Toggle criteria and the distress gate and watch the classification change; the gate can overturn a high count entirely.

nonemildmoderatesevere011
5 of 11 criteria met, distress gate endorsed → classification moderate. This is the article’s Worked Example: five criteria plus endorsed distress falls in the four-to-five band, a moderate classification.