Diets & fasting
19 questions in this area. Each answer starts with the short version, carries an evidence grade and links its sources.
- Are artificial sweeteners and diet soda bad for you or do they cause weight gain?No, sweeteners don't make you fat. In controlled trials they lead, if anything, to slightly lower weight than sugar, not higher. Their long-term health effects are less certain, but nothing there makes an occasional diet soda a problem.
- Are seed oils (like canola and sunflower) toxic and inflammatory?No. In human studies the main fatty acid in seed oils, linoleic acid, is linked to lower risk of cardiovascular disease, not higher, and it doesn't raise the inflammatory markers we can measure in the blood. What deserves attention is less the oil and more what it tends to come with: ultra-processed food.
- Do cheat meals, refeed days or diet breaks actually help when you're dieting?Partly. Refeeds and diet breaks don't reset your metabolism or leptin the way it's often claimed, but a planned break can make a long diet easier to sustain and in some cases seems to protect muscle mass. The benefit is real, the magic isn't.
- Do detox diets and juice cleanses actually flush toxins out of your body?No. Your liver and kidneys already handle that job around the clock, and the research finds no support for a cleanse removing any toxins beyond what your body already clears.
- Do you gain the weight back after stopping GLP-1 (Ozempic/Wegovy)?For most people a large share of the weight returns once the medication is stopped, because appetite comes back and intake creeps up. That is the expected pattern, not a personal failure. Anything about the medication itself belongs with your doctor.
- Does 16:8 intermittent fasting actually help you lose more weight than just eating less?16:8 can work, but not better than other ways of eating less. The time window has no magic of its own — it helps some people take in fewer calories, and no benefit beyond that has been demonstrated.
- Does eating 6 small meals a day boost your metabolism?No. Your daily burn is set by how much you eat in total, not how often. Spreading the same food across six meals gives more small digestion bumps but the exact same sum over the day.
- Does fasting trigger autophagy and "clean out" your cells?Autophagy is a real cellular process that runs continuously, and fasting can increase it. But the idea that a set number of hours without food "cleans out" your cells rests almost entirely on animal and lab studies. In humans, the effect has been measured directly only in small studies.
- Does intermittent fasting burn your muscle?No, not on its own. As long as you get enough protein across the day and keep up your resistance training, the body holds on to muscle even when you eat within a shorter window. It's protein and training that protect muscle, not the clock.
- Does skipping breakfast make you gain weight?No. Randomised trials show that eating or skipping breakfast makes no difference to your weight. What decides it is how much you take in across the whole day.
- Does the alkaline diet work, and does food pH affect your health?No. Your blood pH is held steady by your kidneys and lungs no matter what you eat, so food can't make the body "acidic" or "alkaline" the way the diet claims. Eating more vegetables is good for you, just not because it changes your pH.
- Does time-restricted eating have health benefits beyond just losing weight?Possibly, but the benefit beyond the weight loss itself is small and uncertain. A few small trials show better blood sugar and blood pressure when weight is held steady, but in larger trials most of it disappears once you account for the weight.
- For weight, does 'clean eating' matter more than how many calories you eat?No. Weight is governed by energy balance, not by whether food is labeled 'clean'. Less-processed food can still help, but because it makes it easier to eat the right amount, not because it cancels the calories.
- Is going gluten-free healthier if you don't have celiac disease?No. If you don't have celiac disease, a wheat allergy or diagnosed gluten sensitivity, there is no health reason to avoid gluten, and gluten-free products often carry less fiber and more sugar and fat than the regular versions.
- Is keto or low-carb faster for losing fat than a normal diet?No. When calories and protein are matched, it makes no difference whether carbs are high or low — fat loss ends up the same. What looks like a fast start on keto is mostly water leaving the body.
- Is low-carb or low-fat better for losing weight?Neither one wins. In head-to-head comparisons the groups lose roughly the same amount of weight, and what decides the outcome is how well the diet can be sustained over time, not the split between carbohydrate and fat.
- Is snacking between meals bad for you?No, not in itself. Snacking is neither good nor bad on its own. What matters is what you choose and how much, not that the food lands between meals.
- Is sugar addictive like a drug?No, not in the way the headlines mean. In humans there is no clear evidence that sugar creates a chemical dependence the way a drug does. What resembles addiction has more to do with sweetness, availability and all-or-nothing bans than with the sugar itself.
- Is the carnivore diet (all-meat) actually healthy?Honestly, we know too little to call it healthy. The research that exists consists of uncontrolled surveys, and the controlled long-term data you would need is missing. Some people feel better in the short term, but there is no solid evidence that an all-meat diet is a healthy long-term choice.