Yes, you can eat too many nuts, leading to digestive issues (gas, bloating, diarrhea), weight gain (due to high calories/fat), and potential mineral toxicity (like selenium from Brazil nuts), so portion control (a small handful daily) is key, opting for unsalted, raw, or sprouted varieties for best results.
Summary: Overeating nuts most commonly causes gas, bloating, abdominal cramping and diarrhea (via high fiber, fermentable carbohydrates, and fat). Less commonly it can trigger obstruction, worsen existing GI disease, or cause allergic GI symptoms.
Recommended daily serving of nuts
The Australian Dietary Guidelines recommend 30 grams of nuts on most days of the week for adults. As all nuts have a similar nutrient content, a wide variety of nuts can be included as part of a healthy diet. One serving is approximately 30 grams – or 1/3 of a cup (or one handful).
Worst nuts for your diet
Ounce for ounce, macadamia nuts (10 to 12 nuts; 2 grams protein, 21 grams fat) and pecans (18 to 20 halves; 3 grams protein, 20 grams fat) have the most calories - 200 each - along with the lowest amounts of protein and the highest amounts of fats.
Yes--snacking on nuts throughout the day can be a healthy pattern when done intentionally. Nuts are nutrient-dense, satiating, and associated with reduced risk of cardiovascular disease and improved weight management, but portion control, variety, and timing matter.
Almonds, macadamia nuts, hazelnuts and pecans also appear to be quite heart healthy. So are peanuts — though they are technically not a nut, but a legume, like beans. It's best to choose unsalted or unsweetened nuts. Adding salt or sugar to nuts may cancel out their heart-healthy benefits.
Earth-grown proteins such as beans, nuts, and seeds tend to be good sources of fiber and healthy fats, including omega-3 fatty acids. But eat in moderation: some nuts and seeds, including chia and almonds, are high in oxalates, which contribute to kidney stones. Soybeans, pecans, and flax seeds are nice alternatives.
Nuts like almonds and walnuts contain healthy fats, protein, and fiber. These nutrients help increase satiety, regulate hunger hormones, and speed up fat burning.
Brazil Nuts – Proceed with Caution
Eating too many Brazil nuts can lead to toxic levels of selenium in the body (selenosis) and cause symptoms such as bad breath, diarrhea, nausea, skin rashes/lesions, nerve pain and fatigue. In rare cases, very high levels can cause kidney failure, cardiac arrest and even death.
Symptoms
No, nuts are not classed as fruits or vegetables and therefore do not count towards your 5-a-day. Nuts and seeds are considered healthy sources of fat and are beneficial in their own right, containing many of the minerals we need to stay healthy as well as heart-healthy unsaturated fat and fibre.
Plant foods like nuts are rich in phytochemicals and other antioxidant nutrients, with a potential to counteract oxidative stress and inflammation.
According to nutrition experts, the ideal serving is 15–20 cashew nuts per day, which is about a small handful (30 grams). This amount provides your body with enough protein, fiber, and healthy fats to support heart health, brain function, and stable energy levels throughout the day.
3 Subtle Side Effects of Eating Too Many Nuts, According to...
We found a statistically significant association between high frequency of nut consumption and reduced risk of colorectal cancer. This association was observed for all sub-sites of the colon and rectum among both men and women, with the exception of proximal colon cancer for women.
One of the major benefits of almonds is its vitamin E content. However, if you eat too many and overdose on vitamin E there are some undesirable side effects such as flatulence, diarrhoea, headaches, blurred vision and lethargy.
Although nuts are rich in polyunsaturated fatty acids (PUFA, mainly n-6), dietary fiber and micronutrients such as vitamin E, magnesium, and selenium, they may also contain high levels of one of the most potent carcinogenic substances, the mycotoxin aflatoxin B1 [8].
There's no single "least healthy" nut, as all are nutritious in moderation, but macadamia nuts and pecans are highest in calories, fat, and saturated fat, while lowest in protein, making them less ideal for calorie-counters. Conversely, peanuts can be problematic due to aflatoxin risks, and Brazil nuts offer too much selenium in large doses. The unhealthiest choice depends on your health goals, but generally, raw, unsalted, and unroasted versions of any nut are best, eaten in controlled portions.
But eating too many almonds can actually cause diarrhea and abdominal bloating if your body is not used to processing large amounts of fiber. It's better instead to slowly increase the amount of almonds you are eating if you experience GI problems with this food but want to include more nuts in your diet.
When it comes to nuts for weight loss, almonds are at the top of the list. One review of clinical studies assessed the effects of almonds, cashews, peanuts, hazelnuts, pistachios, walnuts, and mixed nuts on weight loss. The study found that only almonds were associated with a decrease in average body mass and fat mass.
Our absolute top 10 foods for flatter stomachs
Canned foods, some frozen foods, and most processed meats contain large amounts of salt. Snack foods such as chips and crackers are also high in salt. Table salt, some seasonings, ketchup, mustard, and certain sauces such as barbecue, soy, and teriyaki sauces are high in sodium.
Eating too many walnuts can cause stomach discomfort due to their fiber and fat content. Some people with an underlying health condition, such as irritable bowel syndrome (IBS) or diverticulitis, experience stomach symptoms after eating walnuts.
Roasted beans are a nice replacement for nuts in salads. Spiced and roasted chickpeas are a great “nut bowl” snack. Pretzels – Yes, pretzels. KFA member Kathryn shared with us, “I like to use pretzels in place of nuts in recipes, like pie crusts and chicken coatings.