The Food Doctor: Extra Protein Is Making You Fatter!? 6 Food Lies Everyone Still Believes!

Spector explains that around 95% of people get sufficient—or excessive—protein (often ~1.4g/kg vs. the ~0.8g/kg needed), and surplus protein is converted to sugar and stored as fat rather than magically disappearing. In contrast, about 95% of people are deficient in fiber, with only 1 in 20 reaching adequate intake. Increasing fiber by just 5 grams per day (e.g., a handful of nuts/seeds) can reduce risk of death by roughly 14–15%, and two handfuls by around 30%, while also lowering cancer and mental health risks.

Products labeled low-fat, low-sugar, high-protein, or “good for gut health” often contain emulsifiers, stabilizers, sweeteners (like aspartame), and stripped-down ingredients that harm the microbiome and increase appetite. Spector shows that “health halo” foods such as flavored probiotic drinks, light spreads, and protein snack bars are ultra-processed “edible food-like substances.” Studies show low-fat/UPF formulations lead people to overeat substantially in the following day, without any heart-health benefit compared to minimally processed alternatives.

A core goal is 30 different plants per week, including nuts, seeds, herbs, grains, and legumes, not just obvious vegetables. Spector’s “diversity jar” (about 10 types of nuts and seeds kept mixed in a jar) added to yogurt or salads instantly provides ~10 plant types and delivers both fiber and protein. Diverse plant fibers ‘fertilize’ a broader range of microbial species, improving immunity, metabolism, mental health, and resilience to infections and allergies.

Fermentation is simply allowing natural microbes on plants to transform foods under salt and low-oxygen conditions, creating acidic, microbially rich products like sauerkraut, kimchi-style mixes, and fermented veg jars. A basic method: pack chopped leftover veg tightly in a jar, add 2% salt by weight and enough water to cover, keep below the waterline, leave at room temperature for ≥3 days until bubbly, then refrigerate for months. Homemade ferments can contain dozens of beneficial strains versus 2–3 in capsules, and pre-digest plant compounds for better absorption.

Around 95% of people snack, and about a quarter of daily calories in the UK/US now come from snacks—most of them ultra-processed and undoing the benefits of otherwise healthy meals. Late-night snacking causes sugar spikes when the body and gut microbes should be resting, worsening next-day hunger and metabolic responses. Poor sleep similarly increases sugar spikes to the same foods and drives carb cravings; irregular sleep and weekend “social jet lag” disrupt circadian rhythms and microbiome health.

Large studies show that adding exercise alone results in as many people gaining weight as losing it, due to metabolic adaptation, increased appetite, and psychological “I’ve earned this treat” effects. Exercise remains excellent for heart, brain, and longevity, but relying on it to ‘burn off’ a poor diet is ineffective for most. Sustainable weight management comes from improving diet quality (more plants, less ultra-processed food), stabilizing sugar and fat responses, and not triggering compensatory hunger through rigid calorie restriction.

Spector finds little evidence that routine multivitamins, calcium tablets, omega-3 capsules, or 8‑glasses‑a‑day water targets improve health in well-fed populations; calcium supplements may even raise heart risk, and omega‑3 pills don’t prevent heart disease except possibly right after a heart attack. In contrast, coffee (1–4 cups, including decent decaf) consistently correlates with longer life, better heart health, and adds meaningful fiber and polyphenols. Mouthwash and frequent artificially sweetened gum disrupt oral and gut microbes, potentially worsening breath and cravings long term, despite short-term “freshness.”