A — several systematic reviews or trials agree
Side by side
"Keto or fasting — what is actually the difference?" This table is the answer in one screen. It is built from the same structured records that the individual pages are written from, so a cell here cannot say something the page does not: every number carries the id of its source, and a pattern that sets no rule for something says "not set" and why, rather than filling the gap with a plausible figure.
Two things to keep in mind while reading. At twelve months, the differences in weight loss between named patterns are small in the trials that compared them head to head; the columns that separate people are the practical ones lower down — cooking, eating out, the table you sit at. And the "strongest evidence for" row is often not about weight at all, which is worth knowing before choosing a pattern for its reputation.
The filters hide the columns that do not fit your week. If nothing survives them, that is information too.
No pattern on this site fits all of those constraints — which is itself an answer: the fit matters more than the pattern.
| Atkins | Points-based programmes | Zone | DASH | Flexitarian | Mediterranean pattern | Nordic pattern | Volumetrics | Paleo | Vegan eating | Vegetarian eating | Ketogenic diet | Lower-carbohydrate eating | Low-fat eating | Higher-protein eating | Low glycaemic index | Portion control | 5:2 fasting | Alternate-day fasting | Time-restricted eating (16:8) | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Family | commercial programme | commercial programme | commercial programme | dietary pattern | dietary pattern | dietary pattern | dietary pattern | dietary pattern | exclusion | exclusion | exclusion | lower carbohydrate | lower carbohydrate | lower fat | method | method | method | meal timing | meal timing | meal timing |
| Energy approach | eat to appetite (ad libitum) | a fixed daily ceiling | a deficit you choose | a deficit you choose | a deficit you choose | a deficit you choose | a deficit you choose | eat to appetite (ad libitum) | a deficit you choose | a deficit you choose | a deficit you choose | a deficit you choose | a deficit you choose | a deficit you choose | a deficit you choose | a deficit you choose | a deficit you choose | eat to appetite (ad libitum) | eat to appetite (ad libitum) | eat to appetite (ad libitum) |
| Carbohydrate | 20–100 g/day S-KETO-DEFINITION-2015 | not set | 40–40 % S-GE-BMJ-2020 | not set | not set | not set | not set | not set | not set | not set | not set |
≤ 50 g/day S-KETO-DEFINITION-2015 ≤ 10 % S-KETO-DEFINITION-2015 |
50–130 g/day S-KETO-DEFINITION-2015 ≤ 26 % S-KETO-DEFINITION-2015 |
not set | not set | not set | not set | not set | not set | not set |
| Fat | not set | not set | 30–30 % S-GE-BMJ-2020 | not set | not set | 35–40 % S-PREDIMED-2018 | not set | not set | not set | not set | not set | not set | not set | 20–30 % S-NASEM-AMDR-2005 | not set | not set | not set | not set | not set | not set |
| Protein | not set | not set | not set | not set | not set | not set | not set | not set | not set | not set | not set | not set | not set | not set | 1.2–1.6 g/kg S-AHS-PROTEIN-2020 | not set | not set | not set | not set | not set |
| Eating window / meals | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
8 hours S-TREAT-2020 2–3 meals S-TREAT-2020 |
| Excluded or limited |
excluded: added sugar
limited: grains, starchy vegetables, fruit, legumes
|
limited: added sugar, processed foods
|
limited: added sugar, processed foods
|
limited: added sugar, meat, processed foods
|
limited: meat
|
limited: meat, added sugar, processed foods, alcohol
|
limited: meat, added sugar, processed foods
|
limited: processed foods, added sugar
|
excluded: grains, legumes, dairy, processed foods, added sugar
|
excluded: meat, fish, eggs, dairy
|
excluded: meat, fish
|
excluded: added sugar, grains, starchy vegetables
limited: legumes, fruit, dairy
|
excluded: added sugar
limited: grains, starchy vegetables, fruit
|
limited: processed foods, added sugar
|
nothing |
limited: added sugar, processed foods
|
nothing | nothing | nothing | nothing |
| Evidence grade | B systematic reviews with limitations | B systematic reviews with limitations | B systematic reviews with limitations | B systematic reviews with limitations | D mechanism, opinion or marketing | B systematic reviews with limitations | C single trials or observational data | C single trials or observational data | C single trials or observational data | B systematic reviews with limitations | B systematic reviews with limitations | B systematic reviews with limitations | A several systematic reviews or trials agree | A several systematic reviews or trials agree | A several systematic reviews or trials agree | B systematic reviews with limitations | B systematic reviews with limitations | B systematic reviews with limitations | B systematic reviews with limitations | B systematic reviews with limitations |
| Weight loss at 12 months | differences between named diets small and mostly not significant at twelve months, with low certainty S-GE-BMJ-2020 | the largest points programme showed about 2.6 % greater weight loss than control or education at twelve months; a meal-delivery programme about 4.9 %; results reported with a published correction S-COMMERCIAL-2015 | differences between named diets small and mostly not significant at twelve months, with low certainty S-GE-BMJ-2020 | not set | not set | 4.1–10.1 kg in Mediterranean arms; more than low-fat (2.9–5.0 kg), similar to other comparator diets (4.7–7.7 kg) S-MANCINI-2016 | not set | not set | not set | not set | not set | in the network meta-analysis, low-carbohydrate programmes (Atkins among them) lost about 4–5 kg more than usual diet at six months; at twelve months the differences between named diets were small and mostly not significant S-GE-BMJ-2020 | healthy low-carbohydrate −6.0 kg vs healthy low-fat −5.3 kg; no significant difference S-DIETFITS-2018 | healthy low-fat −5.3 kg vs healthy low-carbohydrate −6.0 kg; no significant difference S-DIETFITS-2018 | not set | not set | not set | the umbrella review reports sustained weight loss at 6–12 months for modified alternate-day fasting of the 5:2 type versus usual eating, with moderate-quality evidence S-IF-UMBRELLA-2021 | about 6 % of starting weight with alternate-day fasting versus about 5 % with daily restriction after one year; no significant difference, and more dropout in the fasting group S-ADF-2017 | not set |
| Strongest evidence for | a fast, visible start: glycogen and its water in the induction phase, and for some people blunted appetite S-GLYCOGEN-WATER-2015 | the structure and the support — regular contact, a group, a simple budget — which is what the trials test, rather than the points formula itself S-COMMERCIAL-2015 | a fixed, easily remembered split with a generous share of protein — the part that has evidence behind it, for reasons that have nothing to do with the programme's hormonal theory S-GE-BMJ-2020 | lowering blood pressure — the outcome the pattern was designed and tested for; weight is a side effect S-DASH-MA-2016 | describing, without a rule, a plant-forward way of eating that many people already keep and that excludes nothing | fewer major cardiovascular events in people at high risk S-PREDIMED-2018 | an official, sustainability-aware dietary recommendation for a whole region, published under an open licence S-NNR-2023 | reducing energy intake within a meal or a day while keeping the amount of food eaten the same — the mechanism the laboratory studies show consistently S-ROLLS-2017 | removing the most energy-dense processed foods and sugar in one rule, which for some people is simpler than counting S-PALEO-MA-2019 | the largest short-term weight effect among the vegetarian patterns, attributed by the review to energy density and fibre S-VEG-MA-2016 | a modest, consistent short-term weight advantage that the review attributes to lower energy density and higher fibre, not to the absence of meat as such S-VEG-MA-2016 | a fast, visible start (glycogen and its water in the first week or two) and, for some people, blunted appetite S-GLYCOGEN-WATER-2015 | a faster start (water and glycogen) and, for some people, easier appetite control S-GLYCOGEN-WATER-2015 | showing, over two years, that macronutrient composition does not decide the result — all four assigned compositions lost similar weight S-POUNDS-LOST-2009 | preserving lean mass during a deficit, with the signal strengthening above roughly 1.3 g/kg S-PROTEIN-MA-2024 | food choices that are sensible on their own merits — legumes, whole grains, vegetables — whatever they do to the glycaemic curve S-COCHRANE-LOWGI-2023 | a consistent effect of portion, package and tableware size on how much people select and eat in a sitting, across 58 studies S-PORTION-COCHRANE-2015 | a simpler way for some people to create a weekly deficit — two hard days instead of seven moderate ones S-IF-UMBRELLA-2021 | showing, over a full year, that a fasting pattern and a daily deficit of the same energy end in the same place S-ADF-2017 | a simpler way for some people to hold a deficit without counting; over twelve weeks −0.94 kg vs −0.68 kg in the control, no significant difference S-TREAT-2020 |
| Worth watching | fibre and electrolytes in the induction phase, as for any ketogenic phase | nothing | nothing | sodium — the pattern's defining constraint, mostly hidden in bread, cheese and cured food | nothing | nothing | nothing | protein and essential fats — a very low-density plate can be low in both | calcium without dairy, and fibre without grains and legumes | vitamin B12 — no reliable plant source; supplementation or fortified food is required, not optional; protein per day and per meal; iron, calcium, iodine, omega-3 — each has a plant route that must be deliberate | protein per day and per meal — reachable with eggs, dairy, legumes and soy, but not by accident; iron, especially for menstruating women — plant iron is absorbed less well | electrolytes (sodium, potassium, magnesium) in the first weeks — the loss of water carries them; fibre — it falls with carbohydrate | fibre — it falls together with carbohydrate | essential fats and fat-soluble vitamins if fat is pushed far below 20 % of energy | kidney function if there is known kidney disease — higher protein is a doctor's call there | nothing | protein — a smaller portion of everything can leave it short | protein on fast days and across the week; eating on the five non-fast days — the deficit disappears if they compensate | protein across the week — half the days cannot carry it; the non-fast days: in the trial they were structured at 125 % of needs, not free | protein per day — hard to fit into two meals |
| Cost | 2 · some effort | 2 · some effort | 2 · some effort | 2 · some effort | 1 · easy | 2 · some effort | 2 · some effort | 1 · easy | 3 · hard | 1 · easy | 1 · easy | 2 · some effort | 2 · some effort | 1 · easy | 2 · some effort | 1 · easy | 1 · easy | 1 · easy | 1 · easy | 1 · easy |
| Cooking effort | 2 · some effort | 1 · easy | 3 · hard | 2 · some effort | 2 · some effort | 2 · some effort | 2 · some effort | 2 · some effort | 3 · hard | 3 · hard | 2 · some effort | 3 · hard | 2 · some effort | 2 · some effort | 2 · some effort | 2 · some effort | 1 · easy | 1 · easy | 1 · easy | 1 · easy |
| Eating out | 2 · some effort | 1 · easy | 2 · some effort | 2 · some effort | 1 · easy | 1 · easy | 2 · some effort | 2 · some effort | 2 · some effort | 3 · hard | 2 · some effort | 2 · some effort | 2 · some effort | 2 · some effort | 1 · easy | 2 · some effort | 2 · some effort | 2 · some effort | 3 · hard | 2 · some effort |
| Social friction | 3 · hard | 1 · easy | 2 · some effort | 1 · easy | 1 · easy | 1 · easy | 1 · easy | 1 · easy | 3 · hard | 3 · hard | 2 · some effort | 3 · hard | 2 · some effort | 1 · easy | 1 · easy | 1 · easy | 1 · easy | 2 · some effort | 3 · hard | 2 · some effort |
| Pregnancy and breastfeeding | not for | doctor first | doctor first | doctor first | doctor first | doctor first | doctor first | doctor first | doctor first | doctor first | doctor first | not for | doctor first | doctor first | doctor first | doctor first | doctor first | not for | not for | not for |
| Eating-disorder note on the page | no | yes | no | no | no | no | no | no | no | yes | no | yes | no | no | no | no | yes | yes | yes | yes |
| In the app | not supported as a rule | not supported as a rule | not supported as a rule | not supported as a rule | not supported as a rule | soft context, not a guarantee mediterranean | not supported as a rule | not supported as a rule | soft context, not a guarantee paleo | soft context, not a guarantee vegan | soft context, not a guarantee vegetarian | soft context, not a guarantee ketogenic | soft context, not a guarantee lower-carb | not supported as a rule | not supported as a rule | not supported as a rule | not supported as a rule | not supported as a rule | not supported as a rule | not supported as a rule |
Every number carries the id of the source it was taken from; hover to see it, and find it in the page's source list. "Not set" carries the reason. Practicality scores are editorial: 1 easy, 2 some effort, 3 hard.