Mayo or Mustard? The Most Energy-Dense Foods in Your Kitchen.

Nutrition & Science

A tablespoon of olive oil carries about 520 kJ. A tablespoon of mustard carries about 50. Same spoon, ten times the energy.

3,703kJ per 100 g of beef dripping, the most energy-dense food on our list

7.6×the energy in mayo compared with mustard

348kJ per 100 g of mustard, the lightest

Small spoon, big number.

Energy density is how much energy (kilojoules or Calories) a food packs into every 100 g. Fats sit at the top because fat holds 37 kJ per gram, more than double protein or carbohydrate at about 17 kJ.

Below, we rank the everyday ingredients, spreads and condiments that top the list, then show what else each one brings to the table.

Dense doesn't mean bad. Some of the most energy-dense foods are also some of the most nutritious. Use this as a reference, not a rulebook.

The ranking

Mayonnaise sits among butter and nuts. Mustard barely registers.

Pure fats lead at around 3,700 kJ per 100 g, followed by nuts and full-fat mayonnaise. Sugar and honey, often seen as the big offenders, sit well down the list.

Beef dripping3,703 kJ · 885 Cal
Ghee3,701 kJ · 885 Cal
Olive oil3,695 kJ · 883 Cal
Macadamias3,086 kJ · 738 Cal
Butter3,069 kJ · 734 Cal
Pecans2,973 kJ · 711 Cal
Pine nuts2,925 kJ · 699 Cal
Walnuts2,904 kJ · 694 Cal
Brazil nuts2,886 kJ · 690 Cal
Desiccated coconut2,777 kJ · 664 Cal
Tahini2,717 kJ · 649 Cal
Hazelnuts2,689 kJ · 643 Cal
Mayonnaise2,651 kJ · 634 Cal
Peanut butter2,495 kJ · 596 Cal
Almonds2,386 kJ · 570 Cal
Dark chocolate (high cocoa)2,210 kJ · 528 Cal
Potato crisps2,140 kJ · 511 Cal
Bacon (cooked)1,747 kJ · 418 Cal
Cheddar1,686 kJ · 403 Cal
White sugar1,600 kJ · 382 Cal
Parmesan1,565 kJ · 374 Cal
Honey1,162 kJ · 278 Cal
Mustard (cream style)348 kJ · 83 Cal

Energy per 100 g, from the Australian Food Composition Database. Condiments highlighted in blue.

The nutrient profiles

Same energy. Very different value.

Energy is only half the story. Nuts, seeds and cheese deliver protein, fibre and minerals with their kilojoules. Sugar, honey and pure fats deliver little else.

Food (per 100 g)	Protein (g)	Fat (g)	Sat fat (g)	Fibre (g)	Standout nutrients
Beef dripping	0	100	52	0	Little beyond fat
Ghee	0	100	66	0	Vitamin A
Olive oil	0	100	16	0	Vitamin E; mostly monounsaturated fat
Macadamias	7	77	12	8	Manganese, thiamin; mostly monounsaturated fat
Butter	1	82	57	0	Vitamin A
Pecans	10	72	5	8	Manganese, zinc, copper
Pine nuts	13	70	4	5	Manganese, magnesium, zinc, vitamin E
Walnuts	14	69	4	6	Plant omega-3 (ALA), copper
Brazil nuts	14	69	15	9	Selenium (one nut covers a day's needs), magnesium
Desiccated coconut	7	65	58	15	Fibre, copper, manganese
Tahini	20	61	8	14	Calcium, iron, magnesium, copper
Hazelnuts	15	61	3	10	Vitamin E, copper, manganese
Mayonnaise (full fat)	1	67	8	0.5	Vitamin E, plant omega-3 (ALA)
Peanut butter	22	50	9	6	Niacin, vitamin E, magnesium
Almonds	20	51	4	11	Vitamin E, magnesium, calcium
Dark chocolate (high cocoa)	4	30	18	1	Iron, magnesium, copper
Potato crisps	6	33	8	3	Potassium; high in salt
Bacon (cooked)	21	38	15	0	Selenium, niacin; very high in salt
Cheddar	25	33	23	0	Calcium (760 mg), vitamin A
White sugar	0	0	0	0	None
Parmesan	32	27	19	0	Calcium (about 950 mg), protein
Honey	0	0	0	0	Trace only
Mustard (cream style)	6	3	0	4	Low energy; high in salt

Swipe the table sideways on mobile. Values rounded to the nearest gram.

The surprises

Five things you probably didn't expect.

Mustard vs mayo

Mayonnaise has nearly eight times the energy of mustard, gram for gram. Swap one for the other on a sandwich and the condiment drops from around 400 kJ to 50.

Sugar isn't the worst offender

White sugar (1,600 kJ per 100 g) has less than half the energy of olive oil.

Honey is lighter than sugar

It's about 15% water, so it lands at 1,162 kJ per 100 g.

Dark vs milk chocolate: a dead heat

They're almost level on energy (2,210 kJ vs 2,179 per 100 g), but dark has three times the iron and more than twice the magnesium.

Macadamias match butter

Australia's native nut is slightly more energy-dense than butter, but most of its fat is monounsaturated.

Per spoonful, the way we actually eat them

Olive oil (14 g)520 kJ · 124 Cal
Butter (14 g)430 kJ · 103 Cal
Mayonnaise (15 g)400 kJ · 95 Cal
Peanut butter (16 g)400 kJ · 95 Cal
Honey (21 g)245 kJ · 58 Cal
Tomato sauce (15 g)65 kJ · 16 Cal
Mustard, cream style (15 g)50 kJ · 12 Cal

Per level tablespoon, rounded.

Not on the list

The foods with the wrong reputation.

Some foods carry a reputation they don't earn. The "fattening" ones are often mostly water, while the "healthy snacks" quietly rival chips and cheese.

The scapegoats: lower than you'd think

Salmon

965 kJ

Reputation: oily, rich · vs butter, 3,069 kJ

About a third of butter's energy, with protein and omega-3s.

Olives

868 kJ

Reputation: fatty · vs olive oil, 3,695 kJ

Under a quarter of the energy. The salt is the bigger watch-out.

Avocado

653 kJ

Reputation: fattening · vs macadamias, 3,086 kJ

About a fifth of the energy. Mostly water, plus fibre and potassium.

Eggs

533 kJ

Reputation: heavy · vs cheddar, 1,686 kJ

About a third of the energy, with 13 g protein.

Banana

399 kJ

Reputation: too sugary · vs honey, 1,162 kJ

About a third of the energy.

Potato (boiled)

258 kJ

Reputation: carb bomb · vs potato crisps, 2,140 kJ

About an eighth of the energy. Frying and butter add the rest.

The health halos: higher than you'd think

Coconut oil

3,689 kJ

Reputation: superfood · vs butter, 3,069 kJ

About 20% more energy than butter, and more saturated fat (87 g vs 57 g).

Banana chips

2,171 kJ

Reputation: fruit snack · vs potato crisps, 2,140 kJ

Slightly more energy than potato crisps. They're usually deep-fried and sweetened.

Granola

1,776 kJ

Reputation: healthy breakfast · vs cheddar, 1,686 kJ

A little more energy than cheddar, from the oil and sugar in the bake.

Rice crackers

1,626 kJ

Reputation: light snack · vs cheddar, 1,686 kJ

About the same per gram. They just weigh very little.

Dried dates

1,212 kJ

Reputation: natural sweet · vs honey, 1,162 kJ

Slightly more energy than honey, though they do bring fibre and potassium.

All values per 100 g. Packaged products vary, especially granola and banana chips, so check the label.

Putting it to use

Every spoonful counts. Make it count for something.

01 / Watching your weight

Measure oils, spreads and nut butters rather than pouring or scooping. A "splash" of oil is often three tablespoons.

02 / Small appetite

Energy-dense foods with protein and minerals, like nuts, tahini, peanut butter and parmesan, add a lot to a small plate.

03 / Most value per kilojoule

Favour nuts, seeds and olive oil over sugar, honey and chips. Similar energy, far more nutrients.

04 / Easy swaps

Mustard for mayo. A grating of parmesan for a slab of cheddar. A handful of almonds instead of chips.

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Sources and notes

All figures are per 100 g from the Australian Food Composition Database (Release 3), using generic Australian foods: for example, traditional full-fat mayonnaise, cream-style mustard, raw unsalted nuts, salted butter and cooked middle-rasher bacon. Calories converted at 4.184 kJ per Cal. Brand products vary.

Australian Food Composition Database, Release 3, Food Standards Australia New Zealand

This article is general information only and is not a substitute for advice from your doctor or dietitian. Always read the label. Follow directions for use. Vitamin and mineral supplements should not replace a balanced diet.