Why sustaining a calorie deficit can become difficult

The planned deficit and the achieved deficit

An intended calorie reduction is a behavioural prescription. The achieved energy deficit also depends on actual intake and changing expenditure. A plateau can therefore reflect several processes; it cannot identify their relative contribution by itself.

Polidori and colleagues used a model of a 52-week canagliflozin trial to estimate appetite compensation of roughly 100 kcal/day per kilogram lost [1]. The estimate supports feedback pressure on intake, but came from drug-induced energy loss rather than direct observation of a voluntary diet.

Persistent hunger is a plausible obstacle

Sumithran and colleagues followed participants after a very-low-energy diet. Increased hunger and several appetite-related hormonal changes remained detectable one year later [2]. This supports measuring the physiological experience of maintaining lost weight. The uncontrolled intervention does not establish that all deficits inevitably fail.

Adherence needs its own explanation

In a trial comparing four diets, weight loss was associated with reported adherence rather than assigned diet type [3]. Adherence itself was not randomized. Food access, preferences, support, appetite and measurement error may all contribute.

Paper 2 could test whether baseline EPK predicts subsequent intake variability or adherence after accounting for these factors. Keep baseline intake and later outcomes in separate time windows to reduce mathematical overlap. Papers 1 and 5 provide the physiological context; none of these studies validates their thresholds.

The question in Consistent Eating

Billy Craig’s Consistent Eating (2018, pp.24–32) describes an exploratory observational study of self-directed dieting. Its account raises questions about differences between intended targets and recorded intake. The original thesis and statistical output remain necessary to verify the numerical results and exploratory associations. The study is part of the history of the EPK question, rather than independent validation of the framework.

Related working papers

Read the relevant PDFs: EPK–001 to 007 are the revised version 1.2 papers; EPK–008 to 010 are version 1.0 supplements. Earlier PDFs and DOI records remain on the paper archive.