Nutrients in food do not always reach your body, and according to research reviewed by Gram, the reasons include food preparation, digestion, illness, and cost. A 2026 review of at least seven major databases found that fortification and supplements can fix specific shortages, but dietary variety and better access to food matter just as much.
According to research reviewed by Gram, the nutrients listed on a food label do not always reach your body in the amounts printed there. This 2026 narrative review in Food Science & Nutrition examined how food is grown, prepared, and stored, how the body digests and uses nutrients, and how easily people can get food at all. Some plant compounds can block nutrients such as iron or zinc, while cooking, soaking, or fermenting can make them easier to absorb. Illness, genetics, cost, and limited access also play a role. The authors concluded that fortified foods and supplements can fix specific, well-defined shortages, but they work best alongside varied diets, safe food storage, and fair food policies. The review did not test people directly, so its advice rests on the existing body of research.
Key Statistics
A 2026 narrative review that searched at least seven major research databases found that getting nutrients from food depends on release during digestion, absorption, the body’s use of them, and access to food, not just the amount printed on a label.
The review found that food processing and preparation can either block or boost nutrient availability depending on the dose, the food matrix, and the cooking method, so no single preparation rule applies to every food.
The Quick Take
- What they studied: The researchers asked why eating nutrient-rich foods does not always lead to getting enough nutrients, and what can be done about it.
- Who participated: This was a review of previously published studies rather than a study with people. No participant group was recruited, so no sample size applies.
- Key finding: Getting nutrients from food depends on several steps: release from the food, absorption in the gut, use by the body, and access to food. Each step can be affected by food preparation, plant compounds, illness, and social barriers.
- What it means for you: Eating a wide variety of foods and preparing them in ways that improve absorption may help your body get more of what it needs. If you think you have a specific nutrient shortage, a doctor or dietitian can test for it and recommend the right fix.
The Research Details
This was a narrative review, which means the authors gathered and organized findings from a large body of published research rather than running their own experiment. They searched at least seven major research databases, including PubMed, Scopus, Web of Science, and the Cochrane Library, for studies on how nutrients move from food into the body.
The authors sorted the evidence into five themes: nutrient content, bioaccessibility (how much of a nutrient is released from food during digestion), bioavailability (how much is actually absorbed), utilization (how the body uses it), and population access. They also separated lab and animal studies from studies involving humans, since results from test tubes do not always apply to real people.
The review then looked at how food processing, storage, farming conditions, illness, genetics, and economic hardship shape the final nutrient supply. It ended by comparing strategies such as fortification, supplementation, and food policy to see which approaches appear to work and under what conditions.
A narrative review is useful for seeing the big picture. Nutrient absorption involves many connected steps, and a single experiment rarely captures all of them. By combining lab findings, human absorption studies, and program-level evidence, the authors show where a promising idea in the lab may not hold up in everyday life.
Narrative reviews are not systematic reviews, so the authors did not follow a strict, pre-set method for choosing and scoring every study. This means selection could be influenced by the authors’ judgment. The review does clearly separate strong human evidence from weaker lab evidence, which helps readers judge how much weight each claim deserves. It was published in a peer-reviewed journal.
What the Results Show
The review found that the nutrient content printed on a food is only the starting point. Before a nutrient can help you, it has to be released from the food during digestion, absorbed through the gut lining, and then used by the body. Problems at any of these steps can reduce the benefit, even when the food is rich in that nutrient.
Processing and bioactive compounds, which are natural substances found in plants, can work in either direction. Some compounds, such as certain plant chemicals, can bind to minerals and make them harder to absorb. Other preparation methods can make nutrients more available. The effect depends on how much is consumed, what the rest of the food contains, and how it is prepared, so no single rule applies to every food.
The review also emphasized that a healthy food supply does not guarantee healthy people. Illness, genetic differences, and the body’s own state can prevent nutrients from being used well. Structural barriers, such as high prices or limited access to fresh food, can keep people from eating nutrient-rich foods at all.
Fortification, which means adding nutrients to common foods, and supplementation can be effective for clearly defined deficiencies. However, the authors noted that their impact depends on how widely they reach people, whether they are safe and affordable, how varied the diet is, and whether anyone monitors results.
The authors noted that some newer food technologies could improve nutrition in the future, but they need more evidence about effects on human health, safety, and cost before they are widely used. This matters because promising products can look good in the lab yet fail in real communities. The review also stressed that the most effective strategies are usually combinations, such as safer food storage paired with dietary variety and better farming practices. Solutions that work in one region may need adjustment in another.
The review fits with a long-standing view in nutrition science that food composition tables do not tell the whole story. Researchers have known for decades that plant compounds can limit mineral absorption and that cooking methods can change nutrient availability. This review brings those threads together with evidence on food access and policy, which is a broader focus than many single studies offer.
Because this is a narrative review, it does not measure outcomes in a new group of people, and it does not provide a numerical estimate of how much nutrient absorption changes in any population. The authors did not report a sample size because they were summarizing existing research. Their selection of studies was not fully systematic, so some relevant research may have been left out or weighted differently. Much of the evidence on emerging technologies is still limited, and the authors themselves say more human studies are needed.
The Bottom Line
Eating a varied diet is supported by the review as a practical way to reduce nutrient gaps. Confidence in this advice is high because it aligns with broad nutrition evidence. Targeted fortification or supplementation is supported for defined deficiencies, with moderate confidence, since benefits depend on dose, safety, and whether the product reaches the people who need it. Preparation methods that improve nutrient availability may help, but results vary by food, so confidence is lower for specific techniques.
People who eat limited diets, those with digestive conditions or chronic illness, older adults, pregnant people, and anyone living with restricted food access may find these findings especially relevant. People who already eat a varied diet and have no known deficiency are unlikely to need major changes. Anyone considering high-dose supplements should speak with a healthcare professional first.
Changes in food variety or preparation may improve intake within days or weeks, but changes in nutrient status, such as blood levels of iron or vitamins, typically take several weeks to months to show up on a test. Results depend on the individual, the nutrient involved, and any underlying health conditions.
Frequently Asked Questions
Does the amount of nutrients listed on a food label mean my body absorbs all of them?
Not necessarily. A 2026 review in Food Science & Nutrition explains that nutrients must be released from food, absorbed through the gut, and then used by the body. Plant compounds, preparation methods, illness, and genetics can all reduce how much your body actually gets.
Can cooking or soaking foods make their nutrients easier to absorb?
Sometimes. The review found that processing and preparation can either inhibit or improve nutrient availability, depending on the dose, the food, and the method used. Results vary by food, so no single preparation method works for every nutrient.
Are fortified foods and supplements enough to fix nutrient gaps?
They can work well for specific, clearly defined deficiencies. However, the 2026 review states that coverage, safety, affordability, dietary variety, and monitoring determine whether they meaningfully improve health across a population.
What helps people get enough nutrients from their food?
The review recommends context-specific combinations, including safer processing and storage, dietary diversification, better farming practices, targeted nutrition services, and fair food policies. Because no single strategy works everywhere, local conditions shape which approach is most effective.
Want to Apply This Research?
- Log the number of different whole foods eaten each week, such as vegetables, fruits, whole grains, legumes, and protein sources. Aim to track at least 20 to 30 different plant foods per week, a goal often used in nutrition research on dietary diversity, and note how each meal was prepared (raw, cooked, soaked, or fermented).
- Try one new food or one new preparation method each week, such as soaking beans overnight or adding a vitamin C source like citrus or peppers to iron-rich meals. Pair plant iron sources with vitamin C to support absorption, and avoid drinking tea or coffee right during iron-rich meals if you are concerned about iron levels.
- Review your food diversity log monthly and look for patterns, such as repeatedly skipping certain food groups. Every three to six months, discuss your eating patterns and any symptoms of deficiency with a healthcare provider, and ask about blood tests if you suspect a shortage. Update your app goals as your health or circumstances change.
This article summarizes a narrative review of previously published research and does not describe a new study of people. It is for general information only and is not medical advice. Nutrient needs vary by age, health status, and medications. Consult a doctor, registered dietitian, or other qualified healthcare professional before changing your diet, starting supplements, or treating a suspected deficiency.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.