DietDelta: A Vision-Language Approach for Dietary Assessment via Before-and-After Images

TL;DR

DietDelta introduces a vision-language framework that accurately assesses individual food items and their consumption from paired before-and-after images without requiring complex segmentation or depth sensing.

Contribution

It presents a novel approach leveraging natural language prompts and paired images for precise food-level nutritional analysis, surpassing existing methods.

Findings

Consistently outperforms existing dietary image analysis methods.

Effective in localizing and estimating weights of specific food items.

Establishes a new baseline for before-and-after dietary image assessment.

Abstract

Accurate dietary assessment is critical for precision nutrition, yet most image-based methods rely on a single pre-consumption image and provide only coarse, meal-level estimates. These approaches cannot determine what was actually consumed and often require restrictive inputs such as depth sensing, multi-view imagery, or explicit segmentation. In this paper, we propose a simple vision-language framework for food-item-level nutritional analysis using paired before-and-after eating images. Instead of relying on rigid segmentation masks, our method leverages natural language prompts to localize specific food items and estimate their weight directly from a single RGB image. We further estimate food consumption by predicting weight differences between paired images using a two-stage training strategy. We evaluate our method on three publicly available datasets and demonstrate consistent improvements over existing approaches, establishing a strong baseline for before-and-after dietary image analysis.