30 days no added sugar: deep sleep up, mood flat

The flat mood is the part I'd dig into. When I did a no-sugar month, my HRV dropped for two weeks before rebounding. Did you keep training load steady?

Same here, deep sleep up but gym RPE felt tw opoints harder. I added rice before lifting and the flatness lifted. Not saying it's magic, just my n=1.

Rice isn't the same as the added sugar I cut. Timing around workouts changed how I felt, even with fasting glucose staying at 93.

I ran a six-week no-added-sugar stretch and logged CGM. Fasting glucose went 101 to 94, and my sleep score improved mostly in the first ten days. Weeks three and four were rough: low motivation, harder intervals, and I was definitely under-eating. What helped was keeping protein high and adding carbs around training, not cutting total carbs to zero. If you're flat at day 30, I'd check total calories and training volume before blaming the sugar change. The deep sleep bump can be real and still not enough to offset underfueling. That was my experience, anyway.

My flat mood during a sugar reset turned out to be low iron on routine labs. Totally unrelated to sugar.

Tracking mood and energy at the same times daily is worth the effort. Deep sleep moved in the right direction, but the 3pm slump got worse, and that lined up pretty clearly with eating less overall.

What app are you using for deep sleep?

I did a 21-day no-added-sugar stretch last spring and my tracker showed deep sleep up about 8 minutes and resting HR down 3, but my mood was gray and squats felt like sandbags — the surprise was it wasn’t sugar withdrawal, I’d accidentally dropped ~40g total carbs and 250 calories by cutting flavored yogurt, granola, and my usual post-gym chocolate milk. Once I kept the no-added-sugar rule but added a plain baked potato with dinner and a banana before lifting, my mood came back in about 4 days and my top set went from 125 to 135 again while sleep stayed good. If workouts feel harder, I’d look at total carbs/calories and caffeine timing before blaming the sleep numbers — are you eating enough around training, or did you also cut back on coffee/tea?

Your sleep numbers are probably real, but the flat mood and grindy workouts smell like under-fueling, not sugar withdrawal. I did a month of no sweetened coffee, cereal, or dessert and my sleep score went up about 8 minutes, but I felt like crap until I actually looked at intake and saw I’d dropped ~400 calories/day without meaning to; since I started, it’s stupid easy to under-eat because nothing sounds good. The weird fix was adding a banana or dates before lifting and 30g protein at breakfast, which is technically still no added sugar, and my mood came back around day 8-10 while my squat reps stopped feeling like sandbags. Have you checked total calories/protein, or just the sugar line? That’s where I’d look before calling it an adaptation dip.

I ran a similar 30-day no-added-sugar experiment and saw the same split: deep sleep +8–10 min, RHR down, but mood and gym sessions felt dull. For me the missing variable wasn’t sugar, it was sodium and carb timing. Cutting sweet snacks/sauces also cut a ton of incidental salt, and my harder sessions felt flat until I started salting meals and eating most of my carbs around training. Sleep stayed good. Did your sodium intake or workout-day carb timing change much, or was added sugar the only thing you pulled? Also, are you looking at 7-day rolling averages or single days? The daily mood noise lies.

did you track total carbs or just added sugar? I did a dorm “no added sugar” month and accidentally replaced desserts with low-fat/nonfat stuff, so calories were fine but my pre-lift snack was a rice cake and a prayer. My mood tanked until I added fruit around workouts and a cheap egg/tuna scramble. Curious if your carb timing shifted, especially before training—because my flatness was way more about when carbs showed up than the sugar itself.

For wat it's worth, new here too, only week one, but rooting for your mood to catch up with that sleep win!

For what it's worth, man, same—sleep score up, mood in the gutter, and squats felt like wet sand. Recomp is a troll lol.

Optimization problem: you changed one variable but probably moved three. I had the same flat-mood/grindy-workout thing after cutting added sugar—turned out I’d also dropped total carbs and sodium. Sleep stayed great, but mood and RPE recovered when I kept fruit/potatoes around training and salted meals normally. Did your total carbs/calories/sodium stay flat? If not, you didn’t test no-added-sugar; you tested low-carb + low-sodium.

I ran a no-added-sugar month last fall and got the same split—sleep great, mood blah. What cracked it for me was realizing I missed the ritual, not the sugar. The 3 p.m. cookie was my little reset button. I swapped in a fancy tea and a 10-min walk, and after about two weeks the flatness faded. I also kept frozen mango in the freezer for when I wanted something sweet; still no added sugar, but it kept me from feeling deprived. Did you drop any sweet ritual cold turkey, or was it more of a total sugar sweep? That might explain the mood vs. sleep mismatch.

Same split here: sleep great, workouts grindy, mood very beige. My spreadsheet is smug; I am not.

Same n=1 here: sleep was elite, but my mood ran flat and squats felt like tax season.

I had a similar split, but I think mine was more about the routine than the sugar itself. My after-dinner walk plus cutting my little evening treat improved deep sleep, yet mood felt flat because I’d deleted the cozy ritual and didn’t replace it. Now it’s herbal tea and 10 pages of a library book—same wind-down cue, no added sugar. Workouts also felt grindy until I noticed I’d stopped having a banana before my morning walk. Did your meal timing or pre-workout routine change too, or was sugar the only variable?

same here—great sleep, flat mood, gym felt like molasses. I just logged it and moved on, ha.

Same—sleep was up, mood was backordered. 😂

I did a similar no-added-sugar month and my mood dip tracked with total carbs, not sugar. Once I dropped my lunch banana or potato, afternoon workouts felt dead even though my sleep scores improved. Adding a fist-sized potato back (still no added sugar) got my mood and gym energy back without losing the sleep gain. Did you keep any starchy carbs or fruit, or did it turn into low-carb by accident? Also, any chance the restriction itself made food feel boring/grey? That happened to me around week three and was separate from the tracker numbers.

I tracked my mood like a stock ticker — flat while sleep rallied. Underfueled.

Sending solidarity—sleep gains but flat mood is such a troll. I had to add little joy snacks (non-food ones lol) to feel human.

I’m maintaining these days, and I ran a similar no-sugar month. My deep sleep rose too, but the flat mood only hit when I also dropped my afternoon fruit/yogurt and trained fasted. Once I added a real carb before lifting and kept some starch at dinner, the sleep gains stayed and my mood came back. What was your main added-sugar source before—sweets, flavored coffee, sports drinks? If it was mostly afternoon or liquid, replacing the ritual/timing may matter more than the sugar itself. Also, was that 92 fasting glucose at the same wake time as the 104?

Same—sleep gains real, but my mood was flat until I stopped underfeeding my 4x/week lifting.

Did you keep total carbs and timing steady, or did cutting added sugar also shrink your pre/post-workout carbs? My similar month: deep sleep +10, RHR -3, but intervals felt like wet sand until I put a real carb serving (rice or potato) about 2–3 hours before training. Added sugar stayed at zero. Mood followed workout quality, not the sugar itself. If your total carbs drifted down, that might be the next lever to test — not proof the experiment failed.

Night shift here. Same split for me. Sleep wins, mood meh. I just added fruit back.

Hi, new here too—your flat-mood honesty helps; I’m only week one and already nervous.

Empty-nester here—my reset looked a lot like this after I retired. The odd part was that my flat mood and heavy workouts tracked with sodium, not sugar. Cutting added sugar also meant cutting jarred sauces, bread, flavored yogurt, and deli stuff, so I was way lower on salt without realizing it. Once I started actually salting eggs, soup, and roasted veggies, my walks felt less like slogging and my mood leveled out. Did you track sodium, or just added sugar? Curious if your 30 days also quietly cut a lot of packaged food.

My spreadsheet had the same plot twist: slep up, mood meh, gym like sandbags.

That sleep gain is huge! Flat mood + tough workouts—are you fueling enough? How's your pre-workout snack?

I’ve run that split too. For me it wasn’t sleep—it was losing the little sweet ritual. I kept total carbs similar by adding fruit/yogurt, but mood stayed flat until I moved most carbs to lunch and pre-workout. A banana or rice cake before lifting made workouts way less grindy. Sharp question: did you replace the sugar calories with anything, or just subtract them? If you just subtracted, that’s a different experiment than swapping the source, and it might explain the flat mood more than sugar itself.

Yeah I dropped sugar and my deadlifts fet like sandbags for two weeks, then it evened out.

same here! Cutting sugar tanked my carbs — mood flat, lifts heavy. You tracking total cals?

Did you replace those sugar calories or just delete them? That was my trap: added sugar to zero, but total carbs tanked too. Sleep got better, mood and workouts felt like wet sand until I added a banana and some rice around training and a potato at dinner. Still zero added sugar, but enough fuel for my brain and lifts. I only caught it by logging total carbs for a week, not just the sugar line. Are you eating enough overall? A 30-day cut pls harder workouts is a rough combo.

honestly did your sugar cutoff also nuke your pre-workout carbs? I did a similar dorm-rat version (eggs, tuna packets, dining hall rice) and my deep sleep stayed up, but lifts felt like moving furniture until I added a plain baked potato + frozen berries around lunch. I’d accidentally swapped quick carbs for protein and sadness. Fruit brought mood back without the 2 a.m. wide-awake thing. Curious whether your flat mood tracks with lower-carb days or just the loss of the sweet ritual?

Same here — sleep improved but mood flat until I added fruit back; workouts followed a few weeks later.

the sleep/HR wins are real, but the flat mood screams under-fueled to me. I did 3 weeks no added sugar and my snack drawer went from granola bars to almonds + cheese. Wasn’t tracking total carbs, so I basically went low-carb by accident. Cranky, flat, workouts sucked. Adding back fruit (berries, banana) and a yogurt at night helped within days. Did you log total carbs/calories, or just added sugar? With chaotic kid meals, it’s easy to under-eat and blame sugar.

Curious what your total carbs and sodium did over those 30 days. When I cut added sugar, my sodium tanked because I wasn’t eating as many packaged sauces/snacks — went from ~3,400 to ~1,900 mg/day. Sleep score and RHR improved similarly, but mood and lifting felt flat until I started salting meals and adding a carb around workouts. Did you log sodium/electrolytes or just sugar? Also, was your caffeine intake unchanged? Sugar and caffeine can mask each other, so if caffeine crept up to compensate, that might explain the gr

Airport/hotel twist: I did a no-added-sugar month mostly on the road, and my flat mood tracked with accidentally under-eating breakfast. Hotel buffet = eggs, sausage, coffee, no toast or fruit, then 2pm crash. Workouts felt heavy because I was low on quick carbs. Adding back a real carb at breakfast (oatmeal, banana) while still skipping added sugar brought my mood back without losing the sleep gains. Did your daily calories or breakfast change? And how split were travel vs home days? That might explain the flatness more than sugar itself.

same, my soda swap had me sleeping like a rock but raid nights felt so blah, mood caught up eventually tho

The middle stretch had me foggy and blah too; my morning walks helped more than the scale. Hang in there.

The sleep/HR/glucose wins are real, but flat mood + harder workouts screams underfueling to me. Did you track total carbs and calories, not just added sugar? When I did a no-added-sugar month, I accidentally cut carbs by half and dropped 300–400 kcal/day without noticing. Adding back a piece of fruit and a potato around lifting fixed my mood in about a week, and sleep stayed improved. Also, without the sugar rollercoaster, my afternoon coffee hit way harder, so I moved it earlier. What are your daily carbs/calories now vs before? That might explain the flat mood more than the sugar itself.

I did 3 weeks no added sugar last fall and had the same flat vibe. Mine was because my snack drawer went from yogurt-covered whatevers to almonds/cheese, so I was running a bigger calorie deficit without noticing. Once I added a regular afternoon “second lunch” (eggs, fruit, whatever kid didn’t finish), mood and workouts bounced back. Sleep stayed good. Are you tracking total intake, or just sugar? That’s the piece I missed.

man i did a soda swap month and felt like a sleepy houseplant with a great sleep score lol

Same—sleep score up, squats felt like wet cement. Adding carbs around training helped my mood, not magic tho.

Mine lagged too—sleep fixed first, mood caught up later. Hang in.

Same here—great sleep, flat mood, and leg day felt like molasses. Mine evened out eventually.

Honestly, saaaame, my sleep is elite but my mood missed the memo. Squats felt like wet sand.