I keep seeing "keto" and "low carb" used almost interchangeably online but sometimes people treat them like completely different things. What is the actual difference? I want to make sure I'm doing the right thing before I start.
Good question. Here's the clean distinction:
Low carb: eating fewer carbohydrates than the standard diet, usually 50-150g per day. You may lose weight but won't necessarily be in ketosis.
Ketogenic (keto): eating few enough carbohydrates that your liver starts producing ketone bodies as primary fuel. This requires being under approximately 20-50g net carbs per day. You are metabolically in a different state — ketosis.
Ketosis brings specific benefits beyond just eating fewer carbs: appetite suppression from ketones, more stable energy, and faster fat burning. Low carb gives you some benefits; keto gives you the full picture.
The threshold is really about insulin levels. When carbs are low enough that insulin stays chronically low, the liver signals fat cells to release fatty acids which get converted to ketones. This doesn't happen on "low carb" at 100g per day — insulin is still elevated enough to suppress it.
Practical answer: under 20g net carbs = keto. 50-100g avoiding obvious sugars = low carb. Both can lead to weight loss. Keto is more powerful but requires more commitment and an adaptation period.