Keto, low-fat, Mediterranean and plant-based argue about the food. Their better versions have more in common than the arguments suggest.

Deficiency is real, but it is not the explanation for every vague symptom. When a blood test makes sense, and how to read the units.

Fifty grams? A hundred? The targets differ because they answer different questions. How to work out which number applies to you.

Fiber is a category, not one ingredient. Which type does what, how much you already get, and why the water instructions are not optional.

The long-term picture is largely reassuring, and sleep is usually the deciding factor. What to know about your cup and your timing.

Different sweeteners do different things, and the effect depends on what they replace. A calm look at what the research actually shows.