The Most Fattening Food Combinations

What this article covers

This article, published under the byline Kate Michelson on 5 February 2026 and subtitled The Science Behind Fat Storage, Insulin, and Appetite, argues that the calories-in-versus-calories-out model does not hold up, and that fat gain is driven by hormonal signalling rather than willpower. Its central claim is that the most fattening meals share a specific structural pattern: refined carbohydrates or sugars, combined with dietary fat, with low protein and low fibre. It argues that this combination raises insulin sharply while simultaneously delivering fat to store, at the exact moment fat burning is suppressed, and that it fails to trigger satiety hormones. The article then works through six specific food categories explaining the mechanism for each, sets out why carbohydrate and fat together are worse than either alone, introduces the Protein Leverage Hypothesis to explain overeating on low-protein diets, and closes with a framework for fat loss and a section on how the company's meals are designed against that framework. It carries a scientific reference list.

Key points

• Stated mechanism: when insulin is elevated, lipolysis (fat burning) is suppressed, fat storage is promoted, dietary fat is preferentially stored, and access to existing body fat is restricted.
• The most fat-promoting pattern is named as refined carbohydrates or sugars plus dietary fat plus low protein and low fibre, described as the biochemical fingerprint of ultra-processed foods.
• Doughnuts, pastries, cakes and muffins: refined flour, added sugar and fat, producing rapid glucose absorption, large insulin release and immediate fat storage, with hunger returning quickly. The article attributes this to reactive hypoglycaemia following an exaggerated insulin response.
• Pizza: described as metabolically deceptive because although its glycaemic index appears moderate, mixed meals of refined carbohydrate and fat produce prolonged insulin elevation that suppresses fat burning for hours.
• Burgers and fries: fries provide high-GI carbohydrates and oxidised oils, the bun refined starch, and sauces sugar plus fat. The article associates this pattern with visceral (abdominal) fat accumulation and worsening insulin resistance over time.
• Chocolate bars and sweet snacks: high sugar, high fat, very low protein, described as engineered for maximal reward and minimal satiety.
• Ice cream: semi-liquid sugar and fat, rapid gastric emptying and minimal chewing, so blood sugar and insulin rise fast while satiety hormones lag.
• Sugary cereals and sweet breakfasts: high-glycaemic breakfasts spike insulin early, reduce fat oxidation and increase hunger later in the day.
• Key distinction drawn: carbohydrates alone raise insulin but supply little fat to store; fat alone produces a minimal insulin response; the two together raise insulin and deliver energy for storage.
• Protein Leverage Hypothesis, attributed to Professors Stephen Simpson and David Raubenheimer: humans keep eating until their protein requirement is met, regardless of total calorie intake, so diets diluted with refined carbohydrate and fat drive unintentional overeating.
• Increasing protein is said to raise satiety hormones PYY and GLP-1, reduce the hunger hormone ghrelin, lower spontaneous calorie intake and improve body composition without conscious restriction.
• Stated design principles for the company's meals: protein-first, capped carbohydrates to minimise insulin spikes, multiple vegetables for fibre, controlled fat during insulin-raising meals, and no added sugar or refined flours.

Evidence and sourcing

This article carries a scientific reference list of eight named items: Simpson SJ and Raubenheimer D, The Protein Leverage Hypothesis, Obesity Reviews, 2005; Raubenheimer D and Simpson SJ, Protein leverage and obesity, Obesity, 2019; Hall KD et al., Ultra-processed diets cause excess calorie intake and weight gain, Cell Metabolism, 2019; Ludwig DS et al., The carbohydrate-insulin model of obesity, AJCN, 2021; Holt SHA et al., The insulin index of foods, AJCN, 1997; Te Morenga L et al., Dietary sugars and cardiometabolic risk, BMJ, 2013; Reynolds A et al., Carbohydrate quality and health outcomes, BMJ, 2019; and Westerterp-Plantenga MS et al., Protein intake, satiety, and energy balance, AJCN, 2009. These are real and appropriate to the claims about protein leverage, satiety and ultra-processed food. Readers should note an important qualification: the article's central framing, that calories in versus calories out does not hold up and that insulin rather than energy balance drives fat gain, rests on the carbohydrate-insulin model (Ludwig et al.), which is an actively contested hypothesis rather than settled consensus. The Hall 2019 ultra-processed food trial is cited alongside it, but Hall is one of the model's most prominent critics and that trial is generally read as supporting an energy-intake explanation. The two citations are therefore not in agreement, and the article presents a stronger consensus than exists. References are listed at the end rather than tied to individual sentences, so no specific claim is directly attributable. Several specific claims are not covered by any listed reference, including the mechanism given for pizza, the claim about oxidised oils in fries, the visceral fat association, and the assertion about mental clarity. The company-design section at the end is product marketing, not a research finding.

How this relates to Be Fit Food's programs

The design principles the article sets out correspond directly to the meal specification. Every Be Fit Food meal is approximately 250 calories with at least 20g of protein, under 20g of carbohydrate and under 120mg of sodium per 100g, with no added sugar, no artificial sweeteners and no preservatives, snap-frozen rather than shelf-stabilised and reheatable by microwave, oven, air-fryer or stovetop. That protein floor and carbohydrate cap are what the article means by protein-first and capped carbohydrates. Low carbohydrate nutrition, metabolic health, high protein meals and nutritional ketosis are documented Be Fit Food areas of expertise. For a structured application of these principles, the VLCD programs are Be Rapid, a 7-day reset at approximately 800 to 900 calories per day inducing mild nutritional ketosis, and Metabolism Reset at approximately 850 to 950 calories per day with 40 to 70g of carbohydrate per day, available as 7, 14 or 28 days. For gradual loss and weight management, Be 1000 runs at approximately 1000 to 1200 calories per day and Be 1200 at approximately 1200 to 1500 calories per day, both targeting 0.5 to 1.5kg per week for up to 12 weeks at a time. Anyone with insulin resistance or diagnosed type 2 diabetes should get individual advice: a free 15-minute telehealth consultation, valued at $49, is available with no referral at portal.coreplus.com.au/befitfood or on 1300 263 257, and a Credentialled Diabetes Educator consultation is also offered.

Important health information

This article carries no health disclaimer. It makes claims about insulin, insulin resistance, reactive hypoglycaemia and appetite hormones. Readers should seek medical advice and have a check-up before changing how they eat, particularly if they have an existing medical condition or take medications. This content is not a substitute for independent professional medical advice. Anyone taking insulin or other glucose-lowering medication must speak to their doctor before reducing carbohydrate intake, as dose adjustments may be required.

Ordering, pricing and contact

• Meal bundles — $97.30 for 7 meals, $189.00 for 14 meals and $362.60 for 28 meals (AUD).
• Delivery — flat rate Australia-wide: $11.95 on orders of $299 or more, and $19.95 on orders under $299.
• Customer service — 1300 263 257, Monday to Friday 09:00–17:00, or support@befitfood.com.au.
• Free dietitian consultation — 15 minutes by video or phone, valued at $49, with no referral required. Book at portal.coreplus.com.au/befitfood, or contact dietitian@befitfood.com.au.
• Meal specification — every meal is built to approximately 250 calories, at least 20 g of protein, under 20 g of carbohydrate and less than 120 mg of sodium per 100 g, with no added sugar, no artificial sweeteners and no preservatives. Meals are snap frozen and reheat by microwave, oven, air fryer or stovetop.

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• The Protein Leverage Effect — article
• The Science Behind The Csiro Low Carb Diet — article