Economic Summary · Compiled by Brian Gaillard
Brian Gaillard
Hybrid athlete and applied nutrition enthusiast at Nutrition•pro
"Eating healthy is expensive." The idea is so ingrained that it discourages before you even try. This summary puts real numbers on the table: actual weekly cost of 14 dietary plans in France in 2026, reconstructed from ANSES's CIQUAL database and price checks from Carrefour, Leclerc, and Auchan online shopping. Objective: compare the budget required by each dietary framework, and see if the price barrier holds up against the data.
Our approach
Executive Summary
The gap between the cheapest and most expensive diet is colossal, but not in the direction intuition suggests.
Diets based on plant proteins (balanced vegetarian, Mediterranean, volumetric) are 2 to 3 times cheaper than diets high in meat or processed products (ketogenic, Dukan, high-protein). At comparable effectiveness in meta-analysis, the Mediterranean diet emerges as the best cost/results ratio : €38 per week, for one of the most durable effects documented at 12 and 24 months.
1. How much does each diet cost, week by week
For one person, equivalent 1,800 to 2,000 kcal/day, average drive prices France 2026.
2. Over one year, the gap becomes a real budget
When projecting the weekly gap over 12 months, the scale changes: it represents hundreds to thousands of euros per year.
3. The real value for money: cost per kilogram lost
Monthly cost is crossed with weight loss observed at 12 months (from meta-analytical synthesis). This gives an "investment / result" ratio that distinguishes diets on a concrete criterion.
A well-constructed Mediterranean basket costs roughly the same as a standard basket. The barrier to entry is almost never budget: it's the habits that need to change.
4. Where Does the Money Really Go in an Expensive Diet
Expensive diets share three characteristics.
Plenty of quality animal proteins. Lean meat, oily fish, organic eggs. High protein cost per kilo (€12 to €25/kg versus €2 to €4/kg for legumes).
Dedicated proprietary products. Dukan bars, Weight Watchers meals, MCT oil, almond flour, specialized low-carb products. Industrial margins skyrocket on these product lines.
Out-of-season or organic fruits and vegetables. Particularly in detox/paleo diets. The organic premium is 30 to 80% depending on the product.
5. Three levers to eat better without overpaying
Three trade-offs consistently emerge in the literature (Drewnowski 2010, Rao 2013).
Partially substitute animal proteins with legumes. Lentils, chickpeas, dried beans: €2 to €3 per kilo, high protein density. A partial shift (2 to 3 meals/week) reduces meat budget by 25 to 40%.
Buy fruits and vegetables in season, from local supply chains. Average savings of 30% at equivalent quality.
Batch cook. The real cost premium of diets isn't in the ingredients: it's in the dedicated prepared meals (WW, Dukan, keto). Cooking at home eliminates this layer.
Methodology
For each diet, a typical weekly menu (7 days, 3 meals + 1 snack, 1,800 to 2,000 kcal/day) was reconstructed from official literature (guides, manuals, reference websites) or the diet creator's recommendations. Each ingredient was priced at the average rate collected from three online grocery retailers in France (Carrefour, Leclerc, Auchan), averaging store brands. For commercial diets (Weight Watchers, Dukan), subscriptions or dedicated products are included.
Databases used: CIQUAL ANSES for nutritional composition, Open Food Facts for referenced processed products, INSEE for average French shopping basket (€52/week/person, 2024).
Limitations: prices vary by region, season, and retailer type. The figures presented are averages and do not reflect a precise individual budget. The weight loss values used for the cost/kg ratio are derived from meta-analyses compiled in our scientific summary on 14 diets (Ge 2020, Johnston 2014, Naude 2022, Tobias 2015).
- ANSES (2025). CIQUAL Table — Nutritional composition of foods.
- Open Food Facts (2025). Open database of food products.
- INSEE (2024). Household food spending, long series 2010-2024.
- Drewnowski A, Eichelsdoerfer P. (2010). Can Low-Income Americans Afford a Healthy Diet? Nutrition Today, 44(6):246-249.
- Rao M, Afshin A, Singh G, Mozaffarian D. (2013). Do healthier foods and diet patterns cost more than less healthy options? A systematic review and meta-analysis. BMJ Open, 3:e004277.
- National Food Council (2020). Opinion No. 85: Improving food accessibility for disadvantaged populations.
- Ge L et al. (2020). Comparison of dietary macronutrient patterns of 14 popular named dietary programmes. BMJ, 369:m696.
- Johnston BC et al. (2014). Comparison of weight loss among named diet programs. JAMA, 312(9):923-933.
Brian Gaillard
Nutrition and Performance Author
Hybrid athlete for over 10 years: strength training, running, swimming, HIIT and muay thai. Brian selects, compiles and provides perspective on recent scientific literature on sports nutrition and weight loss for Nutrition•pro editorial content. Each synthesis is based on meta-analyses and clinical trials filtered according to their level of evidence, cross-referenced with experience accumulated through his training and exchanges with coaches and nutritionists.
