The Truth Behind Common Nutrition Myths That Won't Go Away

The fat-makes-you-fat idea became widespread during the low-fat diet era of the 1980s and 1990s, driven partly by early epidemiological research and food industry marketing. In practice, many low-fat products compensate for reduced fat by adding sugar and refined starches — which can increase total calorie intake just as readily.

Dietary fats are essential for absorbing fat-soluble vitamins (A, D, E, and K), supporting cell membrane integrity, and producing hormones. Unsaturated fats — found in foods like olive oil, avocados, and nuts — are associated with favorable cardiovascular outcomes in research. The type of fat matters considerably. For a clearer look at fat categories and their health associations, see our guide to saturated, unsaturated, and trans fats.

Low-carbohydrate diets can be effective for some people in some contexts, but that does not make carbohydrates inherently harmful. Whole food carbohydrate sources — such as legumes, whole grains, fruits, and vegetables — provide dietary fiber, vitamins, minerals, and phytonutrients. Research consistently links higher intake of whole grains and fiber with positive health outcomes.

Refined carbohydrates — white bread, sugary beverages, pastries — are a different matter. These are digested quickly, offer little nutritional density, and can contribute to energy spikes and overconsumption. The distinction is about food quality, not carbohydrates as a macronutrient. For a full picture of what carbs do alongside proteins and fats, this macronutrients explainer breaks it down clearly.

Whether or not breakfast affects weight depends largely on the individual and their overall eating pattern. Some research supports intermittent fasting approaches that naturally delay the first meal of the day — but this is different from simply skipping breakfast and hoping hunger stays manageable. Studies suggest that breakfast skippers often end up consuming more calories at lunch and dinner, partially or fully offsetting any morning deficit.

The takeaway: meal timing and frequency should fit your lifestyle and hunger cues rather than rigid rules. If skipping breakfast consistently leads to overeating later, it is likely not the right strategy for you. Restrictive approaches to meal timing can also trigger cycles of deprivation that are difficult to sustain — an issue explored in depth in this article on why crash diets tend to backfire.

This myth likely stems from observations that late-night eating correlates with weight gain in some populations — but correlation is not causation. Late-night eaters often consume extra calories beyond their daily needs, tend to choose calorie-dense snack foods, and may eat out of boredom or stress rather than genuine hunger. These behaviors, not the clock, drive the outcome.

Metabolic rate does slow slightly during sleep, but this is a modest effect that does not make an evening meal inherently problematic. What you eat and how much you eat over the course of the day matters far more than when the last bite occurs.

Honey, agave nectar, maple syrup, and fruit juice are often marketed as wholesome alternatives to white sugar. While some of these sources contain trace minerals or antioxidants, the amounts are nutritionally modest and do not offset their sugar content meaningfully. Gram for gram, these sweeteners contribute calories in a similar way to table sugar.

Whole fruit is a genuinely different case — the fiber in whole fruit slows digestion, blunts blood glucose response, and contributes to satiety. Fruit juice, having removed most of that fiber, behaves more like a sugary beverage. The distinction between whole food sources and their processed derivatives matters far more than the "natural" label on a package.