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Reading the nutrition label
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In one pass The nutrition panel on the back of a pack lists the energy and main nutrients in the food.
Educational content, not medical advice. See a clinician about your own case.
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Chapter 1
Per 100 mL times the whole bottle
These numbers are concentrations, not the amount you eat. The panel gives values per 100 g, per 100 mL or per serving, and when it uses servings it must say how big one serving is. What your body receives is: the amount per 100 g (or mL) × the grams (or millilitres) you actually eat or drink ÷ 100. Two drinks grabbed for an afternoon slump may have about the same sugar per 100 mL, but if one bottle holds 330 mL and the other 500 mL, finishing each one delivers about 1.5 times as much sugar from the bigger bottle as from the smaller one.
The bigger the package, the more people tend to eat and drink. That is why this multiplication should come first.
Numbers · One serving and the whole pack
A label given per serving is the easiest one to under-read. GB 28050-2011 lets a panel use per 100 g, per 100 mL or per serving, and a per-serving panel must state how many grams or millilitres one serving is. The US Food and Drug Administration (FDA) puts it more bluntly: the serving on a label reflects how much people typically eat or drink at one time, not a recommendation of how much you should have, and if you eat two servings, every nutrient amount and every percentage doubles.So with a per-serving panel, first check how big one serving is, then count how many servings the whole pack holds. With a per-100 g panel, multiply by the actual weight.
The standard covers prepackaged food, and food made to order on the spot does not need this panel, so a milk tea or coffee made fresh at the counter usually comes without these numbers. Bottled milk tea and coffee drinks on the shelf are prepackaged, and their panel still has to be multiplied by the whole bottle.
The current standard makes energy plus four nutrients mandatory, and sugar is not one of them. The new GB 28050-2025, issued in 2025, moves to energy plus six, adding rows for sugar and saturated fat, and takes effect on 16 March 2027. Until then, many packs have no sugar row at all.
Myth · A zero on the label is not always zero
A 0 on the label is a cut-off, not a guarantee of nothing. Under GB 28050-2011, a value is printed as 0 when there is no more than 0.5 g of sugar, 17 kJ of energy or 5 mg of sodium per 100 g or 100 mL.That cut-off is per 100 mL, so the whole bottle needs one more multiplication. A 500 mL drink with sugar printed as 0 can, by this cut-off, hold up to about 2.5 g of sugar. That is an arithmetic ceiling, not a measurement of any particular bottle.
The declared values also come with a tolerance. The same standard allows the measured energy, sugar, sodium, fat and some other values to reach up to 120% of what is printed. A label gives a reliable order of magnitude, not a reading accurate to the gram.
Evidence · Package size changes how much we eat
That package size changes how much people eat is backed by randomized trials. A 2015 Cochrane systematic review by Hollands and colleagues included 72 ; about four in five were in the United States, all came from high-income countries, and the overall risk of bias was unclear or high. Pooled, larger portions, packages or tableware made people eat more, with a standardized mean difference (SMD) of 0.38: 0.46 in adults and 0.21 in children, rated moderate-quality evidence. The authors estimated that removing larger portion sizes across the whole diet over the long term could cut daily intake for UK adults and children by about 144–228 kcal. That is a model extrapolation, not a measurement, and it is uncertain whether shrinking portions that are already small works as well.The other side is how people use labels. A 2011 systematic review by Campos and colleagues covered 120 studies, 96 of them cross-sectional surveys and most from the United States: people widely find nutrition labels credible, but they struggle to understand them and use them correctly. People who read labels tend to have healthier diets, but that is an observed association and does not show that reading labels makes people eat better.
Chapter 2
The denominator in NRV% is not you
How much your own body needs in a day depends on age, sex and how active you are. Under the Chinese dietary reference intakes, the estimated energy requirement for men aged 18 and over is 2250 kcal at a light activity level and 3000 kcal at a heavy one, and for women at a light activity level it is 1800 kcal. A serving of snack whose energy is printed as 20% holds about 400 kcal; in the day of a man doing heavy physical work that is about 13%, and in the day of a lightly active woman about 22%.
The percentages are not all read the same way. The standard writes the reference values for fat and saturated fat as no more than a given amount. The sodium value carries no direction, but the World Health Organization sets a daily upper limit for sodium, so sodium is read as a ceiling too. For protein and dietary fibre the reference value is only a reference amount, not a target the standard sets for you.
Numbers · The reference table and the formula
The main rows of the reference table in Annex A of that national standard are: energy 8400 kJ, set so that protein, fat and carbohydrate supply 13%, 27% and 60% of it; protein 60 g; fat no more than 60 g; saturated fatty acids no more than 20 g; carbohydrate 300 g; dietary fibre 25 g; sodium 2000 mg.The formula is: NRV% = the amount in this serving ÷ NRV × 100%, rounded to a whole number. A serving with 600 mg of sodium, for example, comes to 30%.
Now set that fixed denominator beside personal needs. In China the recommended protein intake is 65 g a day for adult men and 55 g for adult women, 85 g in late pregnancy and 80 g while breastfeeding; the label always uses the same 60 g.
In practice · Borrowing a US rule of thumb
US nutrition labels use a different set of percentages, called percent Daily Value (%DV). The US Food and Drug Administration (FDA) also takes 2000 kcal a day as a general guide, and states that an individual's needs can be higher or lower depending on age, sex, height, weight and physical activity. It offers a rule of thumb: 5% or less per serving is low, and 20% or more is high.That line can be borrowed for a rough pass over NRV%: in the rows you want less of (fat, saturated fat, sodium), look for low numbers, and in the rows you want more of (protein, dietary fibre), look for high ones. But keep in mind that this is the FDA's way of reading US labels, not a clause of the Chinese standard. %DV and NRV% are two systems with their own reference values; they can be compared by analogy, not swapped for each other.
One unit also has to line up: this line is set per serving. If a Chinese label gives NRV% per fixed number of grams or millilitres rather than per serving, first convert it to the amount you actually eat or drink before holding it against the line; otherwise a whole bottle gets under-read.
Myth · Adding up to 100% does not mean enough
Two readings do not hold up. The first treats NRV% as your own requirement. The denominator is a generic adult set at 2000 kcal, while energy requirements are graded by age, sex and activity level, and the gaps between grades can be large.The second treats adding a day's NRV% up to 100% as having eaten enough. For fat and saturated fat the standard writes the reference value as a maximum in the first place, so reaching 100% means touching the reference limit, not meeting a goal. Sodium is best read as a ceiling too. For protein, filling it up means reaching that fixed 60 g, which is not necessarily your amount. And the panel lists only a few rows; filling those rows says nothing about the nutrients the panel does not show.
Chapter 3
After zero sugar, low fat and high protein clear the bar
Clearing the bar covers only that one item. A sugar-free drink may list a non-sugar sweetener among its ingredients, and the World Health Organization (WHO) has a guideline devoted to that group of substances. Some products use sugar alcohols (polyols) instead: in healthy people, the more sugar alcohol eaten, the larger the share that goes unabsorbed, and the more likely gas, abdominal discomfort and a laxative effect become. A low-fat version may carry more sugar: in one comparison using a US food composition database, the low-fat and fat-free versions tested had more sugar overall than the regular ones. High protein says only that the protein row has cleared the bar; for energy and sugar, go back to the panel itself.
Numbers · Where each claim's bar sits
In Annex C of the current national labelling standard, the bars for common claims are as follows, per 100 g or 100 mL:Sugar-free: no more than 0.5 g of sugar; low sugar: no more than 5 gLow fat: no more than 3 g for solids, 1.5 g for liquidsEnergy-free: no more than 17 kJ; low energy: no more than 170 kJ for solids, 80 kJ for liquidsLow sodium: no more than 120 mg of sodiumSource of protein, or contains protein: at least 10% of the protein NRV per 100 g (that is, 6 g), or 5% per 100 mL (3 g), or 5% per 420 kJHigh in protein, or rich in protein: at least 20% per 100 g (12 g), or 10% per 100 mL (6 g), or 10% per 420 kJ
A claim made per serving must meet the per-100 g (or mL) condition as well. All of these are the 2011 conditions; the new version issued in 2025 also changes other details, and no specific figures from it are listed here.
Mechanism · What sugar alcohols do in the gut
When sugar alcohols (polyols) are used as ingredients, they appear on the ingredient list. A 2017 systematic review by Lenhart and Chey covered 79 studies. In healthy people, the more sugar alcohol eaten, the larger the unabsorbed share, and the effect is stronger when several are eaten together. They cause gas, abdominal discomfort and a laxative effect that grow with the dose, in healthy people and in people with irritable bowel syndrome () alike. At moderate doses, bifidobacteria in the gut of healthy people increase.These findings have limits. Studies of how poorly people with IBS absorb sugar alcohols give conflicting results, so the findings cannot be applied to everyone, and sugar alcohols may also disturb gut movement in people with IBS. And the WHO's 2023 guideline on non-sugar sweeteners does not cover sugar alcohols or low-calorie sugars, so not every source of sweetness in a sugar-free product can be read through that guideline.
Myth · Clearing the bar is not the same as healthier
A low-fat version may carry more sugar. In 2016, Nguyen and colleagues used the US Department of Agriculture's nutrient database to compare fat-free, low-fat and regular versions of the same foods: among the foods tested, the low-fat and fat-free versions had more sugar overall than the regular ones. This is a comparison of food composition, limited to US products, and it measured neither what people then ate nor any health outcome; the authors conclude only that foods lower in fat may contain more sugar.That leaves three common misreadings. Sugar-free does not mean energy-free: sugar-free covers only the sugar row, and energy-free is a separate claim of its own. Low fat is not necessarily healthier; it has to be read together with sugar and energy. And a high-protein label does not make something a healthy snack: it says only that the protein row has cleared the bar, and energy, sugar and saturated fat still have to be read off the panel.
Chapter 4
Ingredient order, sugar's many names, and sodium to salt
Sugar is not always called sugar on an ingredient list. White sugar, high fructose corn syrup, glucose, fructose, malt syrup, honey and fruit juice concentrate all count as added sugars. When a product splits its sugar across several names, each name can sit further down the list, while the total is not necessarily small.
Sodium is another row that needs converting. The kidneys hold the volume of fluid outside the cells steady by keeping sodium back or passing it out. Eating moderately less salt for a few weeks lowers blood pressure, and it falls more in people with hypertension. The label gives sodium, not salt: the World Health Organization equates less than 2 g of sodium a day with less than 5 g of salt, so grams of sodium multiplied by about 2.5 is roughly grams of salt. A food labelled with 800 mg of sodium carries about 2 g of salt.
In practice · How the ingredient list is ordered
GB 7718-2011 sets three details for ordering ingredients:Ingredients are listed from most to least by the amount added during manufacture or processing.Ingredients added at no more than 2% need not follow the descending order.A compound ingredient is named, and its own ingredients follow in brackets from most to least. There is one exception: if that compound ingredient already has a national, industry or local standard and makes up less than 25% of the food, its own ingredients need not be listed.
So the brackets do not always hold the full list, and the order within the part below 2% says nothing about which is more. Processing aids also need not be declared, while added water must be.
In practice · The many names of sugar
The US Centers for Disease Control and Prevention (CDC) lists these other names for added sugars: sugar, sucrose, cane sugar, raw sugar, corn syrup, high fructose corn syrup (also called high-fructose syrup), glucose, dextrose, fructose, fruit juice concentrates, fruit nectars (such as agave nectar), honey, malt syrup, maple syrup and molasses.By the CDC's definition, added sugars include sugars added during processing, sugars packaged and sold as sweeteners, the sugar in syrups and honey, and the sugar in concentrated fruit and vegetable juices; the sugar that occurs naturally in milk, fruit and vegetables does not count. This is a public-facing page from a US agency, framed around drinks, not a Chinese labelling regulation.
Evidence · Eating less salt and blood pressure
A by He and colleagues, published in the BMJ in 2013, pooled 34 randomized trials with 3230 participants, each lasting at least 4 weeks. Moderate salt reduction lowered 24-hour urinary sodium by an average of 75 mmol, roughly 4.4 g less salt a day; systolic pressure fell by 4.18 mmHg on average and diastolic by 2.06 mmHg. The fall was larger in people with hypertension (5.39 systolic, 2.82 diastolic mmHg) and smaller in people with normal blood pressure (2.42 systolic, 1.00 diastolic mmHg).None of this means lower sodium is always better or that zero is best. These trials tested moderate reduction and do not say what happens when sodium is pushed very low; and the body needs to keep its sodium within a narrow range, which the kidneys manage by adjusting how much is passed out and how much is kept.
Chapter 5
A convenience-store breakfast, swapped
Take the commercially made cinnamon raisin sweet roll in the US Department of Agriculture's database: per 100 g it has about 372 kcal, 6.2 g of protein, about 31.7 g of total sugars, 2.4 g of dietary fibre and 304 mg of sodium. A large egg has about 72 kcal and about 6.3 g of protein. Note the units differ: the roll is per 100 g and the egg is per egg, so comparing them means converting by the actual weight of the roll in your hand. In short-term trials, the portion with more protein left people feeling fuller. Whole-wheat bread has several times the dietary fibre of white bread. On the drink side, in one small crossover trial the sugar calories people drank were not offset by what they ate afterwards; the story on sugary drinks covers liquid calories in more depth.
The swap is about more protein and fibre and less sugar in liquid form. Apply the three label-reading steps: multiply by the pack size first, then check the sugar and sodium rows, and finally scan the first few places of the ingredient list.
Evidence · Studies of protein and fullness
A 2016 by Dhillon and colleagues compared preloads (a portion of food eaten before the main meal) that were higher or lower in protein. Only 5 studies met the criteria for pooling, and another 28 were used for a directional analysis; both found that the higher-protein portion raised fullness ratings more. The authors state plainly that the result holds under tightly defined conditions, and that extending it to everyday eating, body weight or health outcomes calls for caution.A randomized crossover trial by Leidy and colleagues in 2013 studied 20 young women, about 19 years old on average, who were overweight or obese and usually skipped breakfast. Each arrangement lasted 6 days: a 350 kcal breakfast with 35 g of protein (mainly eggs and beef), one with 13 g of protein (mainly cereal), or continuing to skip breakfast. Both breakfasts reduced hunger compared with skipping, with no difference between them; the high-protein breakfast raised fullness across the day more. Compared with skipping, the high-protein breakfast lowered ghrelin, raised peptide YY (PYY) and cut evening high-fat snacking, while the normal-protein breakfast did none of these. Total daily energy intake did not differ significantly between the arrangements.
The trial was short and small, the two breakfasts also differed in the kind of food, and it was funded by beef and egg industry groups (which state they had no role in design or analysis); it cannot be extended to weight loss or long-term outcomes.
Numbers · The two sides, row by row
Here is the sweet-roll side taken apart (US Department of Agriculture database, commercially made cinnamon raisin sweet roll, per 100 g):Energy 372 kcal, fat 16.4 g, carbohydrate 50.9 gTotal sugars 31.7 g, about six-tenths of the carbohydrateProtein 6.2 g, dietary fibre 2.4 gSodium 304 mg, which by the World Health Organization's sodium-to-salt equivalence is about 0.76 g of salt
This is an older composite record; rolls differ by brand and size, so the one in your hand has to be read off its own label.
On the swap side: the sugar on the label of plain, unsweetened yogurt comes from the milk itself, and fermentation lowers the lactose somewhat. By the CDC's definition, sugar that occurs naturally in milk does not count as added sugar. For flavoured eggs such as tea eggs or braised eggs, read their own sodium row.
In practice · Three steps for this breakfast
Step one: multiply by the pack size. For the drink, multiply the sugar per 100 mL by the bottle's millilitres; for the roll, multiply the per-100 g figures by its actual weight; for a per-serving panel, first check how big a serving is and how many servings the pack holds.Step two: check the sugar and sodium rows. The current standard does not make a sugar row mandatory. When there is none, check where sugar sits in the ingredient list; the carbohydrate row is the ceiling for sugar.
Step three: scan the first few places of the ingredient list and watch for sugar under its various names.
This comparison names no brands, sets no energy or protein target for anyone, and does not claim that only one breakfast in a convenience store is acceptable. It simply applies the three label-reading steps to one common breakfast.
References · 16
- Ministry of Health of the People's Republic of China. (2011). National food safety standard: General rules for nutrition labelling of prepackaged foods (GB 28050-2011). web.archive.org/web/20241006155101/https://www.cirs-reach.com/Uploads/file/20180428/1524880232_75595.pdf
- Hollands, G. J., Shemilt, I., Marteau, T. M., Jebb, S. A., Lewis, H. B., Wei, Y., Higgins, J. P., & Ogilvie, D. (2015). Portion, package or tableware size for changing selection and consumption of food, alcohol and tobacco. Cochrane Database of Systematic Reviews, 2015(9), CD011045. 10.1002/14651858.CD011045.pub2
- National Health and Family Planning Commission of the People's Republic of China. (2017). Chinese dietary reference intakes - Part 1: Macronutrients (WS/T 578.1-2017). Health industry standard; drafted by the Chinese Nutrition Society with the National Institute for Nutrition and Health, China CDC. www.nhc.gov.cn/wjw/yingyang/201710/fdade20feb8144ba921b412944ffb779/files/1739783563332_90405.pdf
- World Health Organization. (2012). Guideline: Sodium intake for adults and children. World Health Organization. www.who.int/publications/i/item/9789241504836
- World Health Organization. (2023). Use of non-sugar sweeteners: WHO guideline. Geneva: WHO. www.who.int/publications/i/item/9789240073616
- Lenhart, A., & Chey, W. D. (2017). A systematic review of the effects of polyols on gastrointestinal health and irritable bowel syndrome. Advances in Nutrition, 8(4), 587-596. 10.3945/an.117.015560
- Nguyen, P. K., Lin, S., & Heidenreich, P. (2016). A systematic comparison of sugar content in low-fat vs regular versions of food. Nutrition & Diabetes, 6(1), e193. 10.1038/nutd.2015.43
- Ministry of Health of the People's Republic of China. (2011). National food safety standard: General standard for the labeling of prepackaged foods (GB 7718-2011). faolex.fao.org/docs/pdf/chn159875.pdf
- Centers for Disease Control and Prevention. (2026, March 5). Rethink your drink. www.cdc.gov/healthy-weight-growth/rethink-your-drink/index.html
- Bernal, A., Zafra, M. A., Simón, M. J., & Mahía, J. (2023). Sodium homeostasis, a balance necessary for life. Nutrients, 15(2), 395. 10.3390/nu15020395
- He, F. J., Li, J., & MacGregor, G. A. (2013). Effect of longer term modest salt reduction on blood pressure: Cochrane systematic review and meta-analysis of randomised trials. BMJ, 346, f1325. 10.1136/bmj.f1325
- U.S. Department of Agriculture, Agricultural Research Service. (2019). FoodData Central: Sweet rolls, cinnamon, commercially prepared with raisins (SR Legacy 175034). fdc.nal.usda.gov/food-details/175034/nutrients
- U.S. Department of Agriculture, Agricultural Research Service. (2019). FoodData Central: Egg, whole / yolk / white, raw, fresh. fdc.nal.usda.gov
- Dhillon, J., Craig, B. A., Leidy, H. J., Amankwaah, A. F., Osei-Boadi Anguah, K., Jacobs, A., Jones, B. L., Jones, J. B., Keeler, C. L., Keller, C. E., McCrory, M. A., Rivera, R. L., Slebodnik, M., Mattes, R. D., & Tucker, R. M. (2016). The effects of increased protein intake on fullness: A meta-analysis and its limitations. Journal of the Academy of Nutrition and Dietetics, 116(6), 968-983. 10.1016/j.jand.2016.01.003
- U.S. Department of Agriculture, Agricultural Research Service. (2019). FoodData Central: Bread, whole-wheat versus white (commercially prepared). fdc.nal.usda.gov
- DiMeglio, D. P., & Mattes, R. D. (2000). Liquid versus solid carbohydrate: effects on food intake and body weight. International Journal of Obesity, 24(6), 794-800. 10.1038/sj.ijo.0801229
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